Rollup merge of rust-lang#140758 - dpaoliello:armhazard, r=jieyouxu

[win][arm64] Disable MSVC Linker 'Arm Hazard' warning

While trying to get the aarch64-msvc build working correctly (rust-lang#140136), I observed the following test failure:

From <rust-lang#140136 (comment)>

```
  = note: main.main.d17f5fbe6225cf88-cgu.0.rcgu.o : fatal error LNK1322: cannot avoid potential ARM hazard (Cortex-A53 MPCore processor bug #843419) in section 0x57; please consider using compiler option /Gy if it was not used
```

This is warning of a code sequence that triggers a bug in Cortex-A53 processors: <https://developer.arm.com/documentation/epm048406/latest>

However, since Windows 10 isn't supported on the Cortex-A53, this warning is not required, so it can be suppressed using the undocumented `/arm64hazardfree` flag.

Author: Zalathar

compiler/rustc_target/src/spec/targets/aarch64_pc_windows_msvc.rs

@@ -1,10 +1,15 @@
-use crate::spec::{Target, TargetMetadata, base};
+use crate::spec::{LinkerFlavor, Lld, Target, TargetMetadata, base};
 
 pub(crate) fn target() -> Target {
     let mut base = base::windows_msvc::opts();
     base.max_atomic_width = Some(128);
     base.features = "+v8a,+neon,+fp-armv8".into();
 
+    // MSVC emits a warning about code that may trip "Cortex-A53 MPCore processor bug #843419" (see
+    // https://developer.arm.com/documentation/epm048406/latest) which is sometimes emitted by LLVM.
+    // Since Arm64 Windows 10+ isn't supported on that processor, it's safe to disable the warning.
+    base.add_pre_link_args(LinkerFlavor::Msvc(Lld::No), &["/arm64hazardfree"]);
+
     Target {
         llvm_target: "aarch64-pc-windows-msvc".into(),
         metadata: TargetMetadata {