Apply temporary unord fix from @beetrees rust-lang#593

Author: tgross35

build.rs

@@ -463,7 +463,6 @@ mod c {
 
         if (target_arch == "aarch64" || target_arch == "arm64ec") && consider_float_intrinsics {
             sources.extend(&[
-                ("__comparetf2", "comparetf2.c"),
                 ("__extenddftf2", "extenddftf2.c"),
                 ("__extendsftf2", "extendsftf2.c"),
                 ("__fixtfdi", "fixtfdi.c"),

src/float/mod.rs

@@ -127,7 +127,20 @@ macro_rules! float_impl {
                 self.to_bits() as Self::SignedInt
             }
             fn eq_repr(self, rhs: Self) -> bool {
-                if self.is_nan() && rhs.is_nan() {
+                #[cfg(feature = "mangled-names")]
+                fn is_nan(x: $ty) -> bool {
+                    // When using mangled-names, the "real" compiler-builtins might not have the
+                    // necessary builtin (__unordtf2) to test whether `f128` is NaN.
+                    // FIXME: Remove once the nightly toolchain has the __unordtf2 builtin
+                    // x is NaN if all the bits of the exponent are set and the significand is non-0
+                    x.repr() & $ty::EXPONENT_MASK == $ty::EXPONENT_MASK
+                        && x.repr() & $ty::SIGNIFICAND_MASK != 0
+                }
+                #[cfg(not(feature = "mangled-names"))]
+                fn is_nan(x: $ty) -> bool {
+                    x.is_nan()
+                }
+                if is_nan(self) && is_nan(rhs) {
                     true
                 } else {
                     self.repr() == rhs.repr()

src/int/big.rs

@@ -11,7 +11,9 @@ const WORD_FULL_MASK: u64 = 0xffffffffffffffff;
 const U128_LO_MASK: u128 = u64::MAX as u128;
 const U128_HI_MASK: u128 = (u64::MAX as u128) << 64;
 
-// Stored little endian
+/// A 256-bit unsigned integer represented as 4 64-bit limbs.
+///
+/// Each limb is a native-endian number, but the array is little-limb-endian.
 #[allow(non_camel_case_types)]
 #[derive(Clone, Copy, Debug, PartialEq, PartialOrd)]
 pub struct u256(pub [u64; 4]);
@@ -32,7 +34,9 @@ impl i256 {
     }
 }
 
-// Stored little endian
+/// A 256-bit signed integer represented as 4 64-bit limbs.
+///
+/// Each limb is a native-endian number, but the array is little-limb-endian.
 #[allow(non_camel_case_types)]
 #[derive(Clone, Copy, Debug, PartialEq, PartialOrd)]
 pub struct i256(pub [u64; 4]);

src/int/mod.rs

@@ -10,8 +10,8 @@ pub mod sdiv;
 pub mod shift;
 pub mod udiv;
 
-pub use leading_zeros::__clzsi2;
 pub use big::{i256, u256};
+pub use leading_zeros::__clzsi2;
 
 public_test_dep! {
 /// Minimal integer implementations needed on all integer types, including wide integers.