Auto merge of #127099 - lqd:revert-126938, r=compiler-errors

Revert "miri: make sure we can find link_section statics even for the local crate"

This PR reverts #126938 as [requested by its author](#127052 (comment)), to fix the #127052 regression.

Fixes #127052

We should probably improve the [`used` rmake test(s)](https://github.com/rust-lang/rust/blob/57931e50409f9365791f7923a68f9ae1ec301c4c/tests/run-make/used/rmake.rs#L7) in the future, but this should do for now.

compiler/rustc_passes/src/reachable.rs

@@ -30,7 +30,7 @@ use rustc_hir::def_id::{DefId, LocalDefId};
 use rustc_hir::intravisit::{self, Visitor};
 use rustc_hir::Node;
 use rustc_middle::bug;
-use rustc_middle::middle::codegen_fn_attrs::CodegenFnAttrFlags;
+use rustc_middle::middle::codegen_fn_attrs::{CodegenFnAttrFlags, CodegenFnAttrs};
 use rustc_middle::middle::privacy::{self, Level};
 use rustc_middle::mir::interpret::{ConstAllocation, ErrorHandled, GlobalAlloc};
 use rustc_middle::query::Providers;
@@ -178,7 +178,15 @@ impl<'tcx> ReachableContext<'tcx> {
         if !self.any_library {
             // If we are building an executable, only explicitly extern
             // types need to be exported.
-            if has_custom_linkage(self.tcx, search_item) {
+            let codegen_attrs = if self.tcx.def_kind(search_item).has_codegen_attrs() {
+                self.tcx.codegen_fn_attrs(search_item)
+            } else {
+                CodegenFnAttrs::EMPTY
+            };
+            let is_extern = codegen_attrs.contains_extern_indicator();
+            let std_internal =
+                codegen_attrs.flags.contains(CodegenFnAttrFlags::RUSTC_STD_INTERNAL_SYMBOL);
+            if is_extern || std_internal {
                 self.reachable_symbols.insert(search_item);
             }
         } else {

tests/ui/linkage-attr/unreferenced-used-static-issue-127052.rs

@@ -0,0 +1,9 @@
+// This is a non-regression test for issue #127052 where unreferenced `#[used]` statics couldn't be
+// removed by the MSVC linker, causing linking errors.
+
+//@ build-pass: needs linking
+//@ only-msvc
+
+#[used]
+static FOO: u32 = 0;
+fn main() {}