[beta] Rollup backports

src/liballoc/collections/binary_heap.rs

@@ -1035,11 +1035,6 @@ impl<'a, T> Iterator for Iter<'a, T> {
     fn size_hint(&self) -> (usize, Option<usize>) {
         self.iter.size_hint()
     }
-
-    #[inline]
-    fn last(mut self) -> Option<&'a T> {
-        self.next_back()
-    }
 }
 
 #[stable(feature = "rust1", since = "1.0.0")]
@@ -1095,11 +1090,6 @@ impl<T> Iterator for IntoIter<T> {
     fn size_hint(&self) -> (usize, Option<usize>) {
         self.iter.size_hint()
     }
-
-    #[inline]
-    fn last(mut self) -> Option<T> {
-        self.next_back()
-    }
 }
 
 #[stable(feature = "rust1", since = "1.0.0")]
@@ -1146,11 +1136,6 @@ impl<T> Iterator for Drain<'_, T> {
     fn size_hint(&self) -> (usize, Option<usize>) {
         self.iter.size_hint()
     }
-
-    #[inline]
-    fn last(mut self) -> Option<T> {
-        self.next_back()
-    }
 }
 
 #[stable(feature = "drain", since = "1.6.0")]

src/liballoc/collections/btree/map.rs

@@ -1193,11 +1193,6 @@ impl<'a, K: 'a, V: 'a> Iterator for Iter<'a, K, V> {
     fn size_hint(&self) -> (usize, Option<usize>) {
         (self.length, Some(self.length))
     }
-
-    #[inline]
-    fn last(mut self) -> Option<(&'a K, &'a V)> {
-        self.next_back()
-    }
 }
 
 #[stable(feature = "fused", since = "1.26.0")]
@@ -1258,11 +1253,6 @@ impl<'a, K: 'a, V: 'a> Iterator for IterMut<'a, K, V> {
     fn size_hint(&self) -> (usize, Option<usize>) {
         (self.length, Some(self.length))
     }
-
-    #[inline]
-    fn last(mut self) -> Option<(&'a K, &'a mut V)> {
-        self.next_back()
-    }
 }
 
 #[stable(feature = "rust1", since = "1.0.0")]
@@ -1369,11 +1359,6 @@ impl<K, V> Iterator for IntoIter<K, V> {
     fn size_hint(&self) -> (usize, Option<usize>) {
         (self.length, Some(self.length))
     }
-
-    #[inline]
-    fn last(mut self) -> Option<(K, V)> {
-        self.next_back()
-    }
 }
 
 #[stable(feature = "rust1", since = "1.0.0")]
@@ -1436,11 +1421,6 @@ impl<'a, K, V> Iterator for Keys<'a, K, V> {
     fn size_hint(&self) -> (usize, Option<usize>) {
         self.inner.size_hint()
     }
-
-    #[inline]
-    fn last(mut self) -> Option<&'a K> {
-        self.next_back()
-    }
 }
 
 #[stable(feature = "rust1", since = "1.0.0")]
@@ -1478,11 +1458,6 @@ impl<'a, K, V> Iterator for Values<'a, K, V> {
     fn size_hint(&self) -> (usize, Option<usize>) {
         self.inner.size_hint()
     }
-
-    #[inline]
-    fn last(mut self) -> Option<&'a V> {
-        self.next_back()
-    }
 }
 
 #[stable(feature = "rust1", since = "1.0.0")]
@@ -1520,11 +1495,6 @@ impl<'a, K, V> Iterator for Range<'a, K, V> {
             unsafe { Some(self.next_unchecked()) }
         }
     }
-
-    #[inline]
-    fn last(mut self) -> Option<(&'a K, &'a V)> {
-        self.next_back()
-    }
 }
 
 #[stable(feature = "map_values_mut", since = "1.10.0")]
@@ -1538,11 +1508,6 @@ impl<'a, K, V> Iterator for ValuesMut<'a, K, V> {
     fn size_hint(&self) -> (usize, Option<usize>) {
         self.inner.size_hint()
     }
-
-    #[inline]
-    fn last(mut self) -> Option<&'a mut V> {
-        self.next_back()
-    }
 }
 
 #[stable(feature = "map_values_mut", since = "1.10.0")]
@@ -1661,11 +1626,6 @@ impl<'a, K, V> Iterator for RangeMut<'a, K, V> {
             unsafe { Some(self.next_unchecked()) }
         }
     }
-
-    #[inline]
-    fn last(mut self) -> Option<(&'a K, &'a mut V)> {
-        self.next_back()
-    }
 }
 
 impl<'a, K, V> RangeMut<'a, K, V> {

src/liballoc/collections/btree/set.rs

@@ -1019,11 +1019,6 @@ impl<'a, T> Iterator for Iter<'a, T> {
     fn size_hint(&self) -> (usize, Option<usize>) {
         self.iter.size_hint()
     }
-
-    #[inline]
-    fn last(mut self) -> Option<&'a T> {
-        self.next_back()
-    }
 }
 #[stable(feature = "rust1", since = "1.0.0")]
 impl<'a, T> DoubleEndedIterator for Iter<'a, T> {
@@ -1049,11 +1044,6 @@ impl<T> Iterator for IntoIter<T> {
     fn size_hint(&self) -> (usize, Option<usize>) {
         self.iter.size_hint()
     }
-
-    #[inline]
-    fn last(mut self) -> Option<T> {
-        self.next_back()
-    }
 }
 #[stable(feature = "rust1", since = "1.0.0")]
 impl<T> DoubleEndedIterator for IntoIter<T> {
@@ -1083,11 +1073,6 @@ impl<'a, T> Iterator for Range<'a, T> {
     fn next(&mut self) -> Option<&'a T> {
         self.iter.next().map(|(k, _)| k)
     }
-
-    #[inline]
-    fn last(mut self) -> Option<&'a T> {
-        self.next_back()
-    }
 }
 
 #[stable(feature = "btree_range", since = "1.17.0")]

src/liballoc/string.rs

@@ -2385,10 +2385,6 @@ impl Iterator for Drain<'_> {
     fn size_hint(&self) -> (usize, Option<usize>) {
         self.iter.size_hint()
     }
-    #[inline]
-    fn last(mut self) -> Option<char> {
-        self.next_back()
-    }
 }
 
 #[stable(feature = "drain", since = "1.6.0")]

src/liballoc/vec.rs

@@ -2395,11 +2395,6 @@ impl<T> Iterator for IntoIter<T> {
     fn count(self) -> usize {
         self.len()
     }
-
-    #[inline]
-    fn last(mut self) -> Option<T> {
-        self.next_back()
-    }
 }
 
 #[stable(feature = "rust1", since = "1.0.0")]
@@ -2519,11 +2514,6 @@ impl<T> Iterator for Drain<'_, T> {
     fn size_hint(&self) -> (usize, Option<usize>) {
         self.iter.size_hint()
     }
-
-    #[inline]
-    fn last(mut self) -> Option<T> {
-        self.next_back()
-    }
 }
 
 #[stable(feature = "drain", since = "1.6.0")]
@@ -2593,10 +2583,6 @@ impl<I: Iterator> Iterator for Splice<'_, I> {
     fn size_hint(&self) -> (usize, Option<usize>) {
         self.drain.size_hint()
     }
-
-    fn last(mut self) -> Option<Self::Item> {
-        self.next_back()
-    }
 }
 
 #[stable(feature = "vec_splice", since = "1.21.0")]

src/libcore/ascii.rs

@@ -117,8 +117,6 @@ impl Iterator for EscapeDefault {
     type Item = u8;
     fn next(&mut self) -> Option<u8> { self.range.next().map(|i| self.data[i]) }
     fn size_hint(&self) -> (usize, Option<usize>) { self.range.size_hint() }
-    #[inline]
-    fn last(mut self) -> Option<u8> { self.next_back() }
 }
 #[stable(feature = "rust1", since = "1.0.0")]
 impl DoubleEndedIterator for EscapeDefault {

src/libcore/iter/adapters/mod.rs

@@ -73,11 +73,6 @@ impl<I> Iterator for Rev<I> where I: DoubleEndedIterator {
     {
         self.iter.position(predicate)
     }
-
-    #[inline]
-    fn last(mut self) -> Option<Self::Item> {
-        self.next_back()
-    }
 }
 
 #[stable(feature = "rust1", since = "1.0.0")]

src/libcore/mem.rs

@@ -466,7 +466,7 @@ pub unsafe fn zeroed<T>() -> T {
 /// [`MaybeUninit<T>`]: union.MaybeUninit.html
 /// [inv]: union.MaybeUninit.html#initialization-invariant
 #[inline]
-#[rustc_deprecated(since = "1.40.0", reason = "use `mem::MaybeUninit` instead")]
+#[rustc_deprecated(since = "1.38.0", reason = "use `mem::MaybeUninit` instead")]
 #[stable(feature = "rust1", since = "1.0.0")]
 pub unsafe fn uninitialized<T>() -> T {
     intrinsics::panic_if_uninhabited::<T>();

src/libcore/slice/mod.rs

@@ -3547,11 +3547,6 @@ impl<'a, T, P> Iterator for Split<'a, T, P> where P: FnMut(&T) -> bool {
             (1, Some(self.v.len() + 1))
         }
     }
-
-    #[inline]
-    fn last(mut self) -> Option<Self::Item> {
-        self.next_back()
-    }
 }
 
 #[stable(feature = "rust1", since = "1.0.0")]
@@ -3650,11 +3645,6 @@ impl<'a, T, P> Iterator for SplitMut<'a, T, P> where P: FnMut(&T) -> bool {
             (1, Some(self.v.len() + 1))
         }
     }
-
-    #[inline]
-    fn last(mut self) -> Option<Self::Item> {
-        self.next_back()
-    }
 }
 
 #[stable(feature = "rust1", since = "1.0.0")]
@@ -3720,11 +3710,6 @@ impl<'a, T, P> Iterator for RSplit<'a, T, P> where P: FnMut(&T) -> bool {
     fn size_hint(&self) -> (usize, Option<usize>) {
         self.inner.size_hint()
     }
-
-    #[inline]
-    fn last(mut self) -> Option<Self::Item> {
-        self.next_back()
-    }
 }
 
 #[stable(feature = "slice_rsplit", since = "1.27.0")]
@@ -3789,11 +3774,6 @@ impl<'a, T, P> Iterator for RSplitMut<'a, T, P> where P: FnMut(&T) -> bool {
     fn size_hint(&self) -> (usize, Option<usize>) {
         self.inner.size_hint()
     }
-
-    #[inline]
-    fn last(mut self) -> Option<Self::Item> {
-        self.next_back()
-    }
 }
 
 #[stable(feature = "slice_rsplit", since = "1.27.0")]

src/libcore/str/mod.rs

@@ -1333,11 +1333,6 @@ impl<'a> Iterator for Lines<'a> {
     fn size_hint(&self) -> (usize, Option<usize>) {
         self.0.size_hint()
     }
-
-    #[inline]
-    fn last(mut self) -> Option<Self::Item> {
-        self.next_back()
-    }
 }
 
 #[stable(feature = "rust1", since = "1.0.0")]
@@ -1384,11 +1379,6 @@ impl<'a> Iterator for LinesAny<'a> {
     fn size_hint(&self) -> (usize, Option<usize>) {
         self.0.size_hint()
     }
-
-    #[inline]
-    fn last(mut self) -> Option<Self::Item> {
-        self.next_back()
-    }
 }
 
 #[stable(feature = "rust1", since = "1.0.0")]
@@ -4231,11 +4221,6 @@ impl<'a> Iterator for SplitWhitespace<'a> {
     fn size_hint(&self) -> (usize, Option<usize>) {
         self.inner.size_hint()
     }
-
-    #[inline]
-    fn last(mut self) -> Option<Self::Item> {
-        self.next_back()
-    }
 }
 
 #[stable(feature = "split_whitespace", since = "1.1.0")]
@@ -4262,11 +4247,6 @@ impl<'a> Iterator for SplitAsciiWhitespace<'a> {
     fn size_hint(&self) -> (usize, Option<usize>) {
         self.inner.size_hint()
     }
-
-    #[inline]
-    fn last(mut self) -> Option<Self::Item> {
-        self.next_back()
-    }
 }
 
 #[stable(feature = "split_ascii_whitespace", since = "1.34.0")]

src/librustc_codegen_llvm/debuginfo/metadata.rs

@@ -31,7 +31,7 @@ use rustc::ty::{self, AdtKind, ParamEnv, Ty, TyCtxt};
 use rustc::ty::layout::{self, Align, Integer, IntegerExt, LayoutOf,
                         PrimitiveExt, Size, TyLayout, VariantIdx};
 use rustc::ty::subst::UnpackedKind;
-use rustc::session::config;
+use rustc::session::config::{self, DebugInfo};
 use rustc::util::nodemap::FxHashMap;
 use rustc_fs_util::path_to_c_string;
 use rustc_data_structures::small_c_str::SmallCStr;
@@ -925,7 +925,26 @@ pub fn compile_unit_metadata(tcx: TyCtxt<'_, '_, '_>,
     let producer = CString::new(producer).unwrap();
     let flags = "\0";
     let split_name = "\0";
-    let kind = DebugEmissionKind::from_generic(tcx.sess.opts.debuginfo);
+
+    // FIXME(#60020):
+    //
+    //    This should actually be
+    //
+    //    ```
+    //      let kind = DebugEmissionKind::from_generic(tcx.sess.opts.debuginfo);
+    //    ```
+    //
+    //    that is, we should set LLVM's emission kind to `LineTablesOnly` if
+    //    we are compiling with "limited" debuginfo. However, some of the
+    //    existing tools relied on slightly more debuginfo being generated than
+    //    would be the case with `LineTablesOnly`, and we did not want to break
+    //    these tools in a "drive-by fix", without a good idea or plan about
+    //    what limited debuginfo should exactly look like. So for now we keep
+    //    the emission kind as `FullDebug`.
+    //
+    //    See https://github.com/rust-lang/rust/issues/60020 for details.
+    let kind = DebugEmissionKind::FullDebug;
+    assert!(tcx.sess.opts.debuginfo != DebugInfo::None);
 
     unsafe {
         let file_metadata = llvm::LLVMRustDIBuilderCreateFile(

src/libstd/env.rs

@@ -746,10 +746,6 @@ impl Iterator for Args {
         self.inner.next().map(|s| s.into_string().unwrap())
     }
     fn size_hint(&self) -> (usize, Option<usize>) { self.inner.size_hint() }
-    #[inline]
-    fn last(mut self) -> Option<String> {
-        self.next_back()
-    }
 }
 
 #[stable(feature = "env", since = "1.0.0")]
@@ -785,8 +781,6 @@ impl Iterator for ArgsOs {
     type Item = OsString;
     fn next(&mut self) -> Option<OsString> { self.inner.next() }
     fn size_hint(&self) -> (usize, Option<usize>) { self.inner.size_hint() }
-    #[inline]
-    fn last(mut self) -> Option<OsString> { self.next_back() }
 }
 
 #[stable(feature = "env", since = "1.0.0")]