core: updated for the master changes.

The master no longer has `std::num::Float`, so a generic `ldexp` is
not readily available. `DecodableFloat::ldexpi` works around this.

src/libcore/num/flt2dec/decoder.rs

@@ -53,15 +53,20 @@ pub enum FullDecoded {
 
 /// A floating point type which can be `decode`d.
 pub trait DecodableFloat: Float + Copy {
+    /// Returns `x * 2^exp`. Almost same to `std::{f32,f64}::ldexp`.
+    /// This is used for testing.
+    fn ldexpi(f: i64, exp: isize) -> Self;
     /// The minimum positive normalized value.
     fn min_pos_norm_value() -> Self;
 }
 
 impl DecodableFloat for f32 {
+    fn ldexpi(f: i64, exp: isize) -> Self { f as Self * (exp as Self).exp2() }
     fn min_pos_norm_value() -> Self { f32::MIN_POSITIVE }
 }
 
 impl DecodableFloat for f64 {
+    fn ldexpi(f: i64, exp: isize) -> Self { f as Self * (exp as Self).exp2() }
     fn min_pos_norm_value() -> Self { f64::MIN_POSITIVE }
 }
 

src/libcoretest/num/flt2dec/estimator.rs

@@ -8,7 +8,7 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-use std::num::Float;
+use std::f64;
 use core::num::flt2dec::estimator::*;
 
 #[test]
@@ -54,7 +54,7 @@ fn test_estimate_scaling_factor() {
     assert_almost_eq!(estimate_scaling_factor(0x1fffffffffffff, 971), 309);
 
     for i in -1074..972 {
-        let expected = Float::ldexp(1.0, i).log10().ceil();
+        let expected = f64::ldexp(1.0, i).log10().ceil();
         assert_almost_eq!(estimate_scaling_factor(1, i as i16), expected as i16);
     }
 }