Unrolled build for #144383

Rollup merge of #144383 - ZuseZ4:disable-f128-on-amdgcn, r=oli-obk

disable cfg.has_reliable_f128 on amdgcn

I was experimenting with compiling a few kernels for amd while working on std::offload. It seems like the logic in rust-lang/compiler-builtins#737 got removed, so I re-introduce it here. Probably should have a test to avoid another regression and make sure that f128 doesn't show up as target feature for amdgcn. It looks like currently we neither check that for nvptx, nor amdgpu. Maybe I could add two revisions to https://github.com/rust-lang/rust/blob/master/tests/ui/float/target-has-reliable-nightly-float.rs?
r? ````@Flakebi````

fixes: #144381

Author: rust-timer

compiler/rustc_codegen_llvm/src/llvm_util.rs

@@ -405,6 +405,8 @@ fn update_target_reliable_float_cfg(sess: &Session, cfg: &mut TargetConfig) {
         ("mips64" | "mips64r6", _) => false,
         // Selection bug <https://github.com/llvm/llvm-project/issues/95471>
         ("nvptx64", _) => false,
+        // Unsupported https://github.com/llvm/llvm-project/issues/121122
+        ("amdgpu", _) => false,
         // ABI bugs <https://github.com/rust-lang/rust/issues/125109> et al. (full
         // list at <https://github.com/rust-lang/rust/issues/116909>)
         ("powerpc" | "powerpc64", _) => false,