Rollup merge of rust-lang#144431 - Gelbpunkt:f128-math-musl, r=petrochenkov,tgross35

Disable has_reliable_f128_math on musl targets

musl does not implement the symbols required by rustc for f128 maths. Disable the associated cfg for all musl targets and adjust the tests accordingly.

Closes rust-lang#144423

Author: tgross35

compiler/rustc_codegen_llvm/src/llvm_util.rs

@@ -433,6 +433,9 @@ fn update_target_reliable_float_cfg(sess: &Session, cfg: &mut TargetConfig) {
         // This rules out anything that doesn't have `long double` = `binary128`; <= 32 bits
         // (ld is `f64`), anything other than Linux (Windows and MacOS use `f64`), and `x86`
         // (ld is 80-bit extended precision).
+        //
+        // musl does not implement the symbols required for f128 math at all.
+        _ if target_env == "musl" => false,
         ("x86_64", _) => false,
         (_, "linux") if target_pointer_width == 64 => true,
         _ => false,

tests/ui/float/target-has-reliable-nightly-float.rs

@@ -19,8 +19,10 @@ pub fn has_f128() {}
 pub fn has_f128_math() {}
 
 fn main() {
-    if cfg!(target_arch = "aarch64") && cfg!(target_os = "linux") {
-        // Aarch64+Linux is one target that has support for all features, so use it to spot
+    if cfg!(target_arch = "aarch64") &&
+        cfg!(target_os = "linux") &&
+        cfg!(not(target_env = "musl")) {
+        // Aarch64+GNU+Linux is one target that has support for all features, so use it to spot
         // check that the compiler does indeed enable these gates.
 
         assert!(cfg!(target_has_reliable_f16));