Auto merge of #138022 - tgross35:s390x-f16-test, r=<try>

[experiment] enable f16 on s390x

Pick up https://github.com/llvm/llvm-project/pull and see if we can get artifacts for s390x.

try-job: dist-s390x-linux

Author: bors

.gitmodules

@@ -28,8 +28,8 @@
 	shallow = true
 [submodule "src/llvm-project"]
 	path = src/llvm-project
-	url = https://github.com/rust-lang/llvm-project.git
-	branch = rustc/20.1-2025-02-13
+	url = https://github.com/tgross35/llvm-project.git
+	branch = s390x-f16
 	shallow = true
 [submodule "src/doc/embedded-book"]
 	path = src/doc/embedded-book

library/std/build.rs

@@ -102,8 +102,6 @@ fn main() {
     let has_reliable_f16 = match (target_arch.as_str(), target_os.as_str()) {
         // We can always enable these in Miri as that is not affected by codegen bugs.
         _ if is_miri => true,
-        // Selection failure <https://github.com/llvm/llvm-project/issues/50374>
-        ("s390x", _) => false,
         // Unsupported <https://github.com/llvm/llvm-project/issues/94434>
         ("arm64ec", _) => false,
         // LLVM crash <https://github.com/llvm/llvm-project/issues/129394>