Enable xray support for Mac

* https://maskray.me/blog/2023-06-18-port-llvm-xray-to-apple-systems
* https://github.com/llvm/llvm-project/blob/llvmorg-20.1.4/clang/lib/Driver/XRayArgs.cpp#L31

Author: quininer

compiler/rustc_target/src/spec/targets/aarch64_apple_darwin.rs

@@ -22,6 +22,7 @@ pub(crate) fn target() -> Target {
             max_atomic_width: Some(128),
             // FIXME: The leak sanitizer currently fails the tests, see #88132.
             supported_sanitizers: SanitizerSet::ADDRESS | SanitizerSet::CFI | SanitizerSet::THREAD,
+            supports_xray: true,
             ..opts
         },
     }

compiler/rustc_target/src/spec/targets/x86_64_apple_darwin.rs

@@ -23,6 +23,7 @@ pub(crate) fn target() -> Target {
                 | SanitizerSet::CFI
                 | SanitizerSet::LEAK
                 | SanitizerSet::THREAD,
+            supports_xray: true,
             ..opts
         },
     }

tests/ui/instrument-xray/target-not-supported.rs

@@ -1,7 +1,7 @@
 // Verifies that `-Z instrument-xray` cannot be used with unsupported targets,
 //
 //@ needs-llvm-components: x86
-//@ compile-flags: -Z instrument-xray --target x86_64-apple-darwin
+//@ compile-flags: -Z instrument-xray --target x86_64-pc-windows-msvc
 
 #![feature(no_core)]
 #![no_core]