Rollup merge of #90044 - rusticstuff:disable_arm_outline_atomics_for_musl, r=workingjubilee

Restrict aarch64 outline atomics to glibc for now.

The introduced dependency on `getauxval` causes linking problems with musl, making compiling any binaries for `aarch64-unknown-linux-musl` impossible without workarounds such as using lld or adding liblibc.rlib again to the linker invocation, see #89626.

This is a workaround until libc>0.2.108 is merged.

compiler/rustc_target/src/spec/aarch64_unknown_linux_musl.rs

@@ -9,10 +9,6 @@ pub fn target() -> Target {
         pointer_width: 64,
         data_layout: "e-m:e-i8:8:32-i16:16:32-i64:64-i128:128-n32:64-S128".to_string(),
         arch: "aarch64".to_string(),
-        options: TargetOptions {
-            features: "+outline-atomics".to_string(),
-            mcount: "\u{1}_mcount".to_string(),
-            ..base
-        },
+        options: TargetOptions { mcount: "\u{1}_mcount".to_string(), ..base },
     }
 }