powerpc{,64,64le} clang triplet includes elfv{1,2} with rust 1.90.0

[sertonix]

Recently firefox started failing to compile on powerpc with errors like warning: glslopt@0.1.11: clang-20: error: version 'elfv2' in target triple 'powerpc64le-alpine-linux-muslelfv2' is invalid.

If I understood the issue correctly this happens since rust-lang/rust#142321 cause elfv2 (and elfv1) are appended to the target triplet when creating the clang target.

This patch fixed compilation of firefox but I would like advice if this is the right way to fix the compilation failure. One thing I wondered is if -mabi=elfv1 and -mabi=elfv2 should be passed explicitly to ensure the compiler uses the correct abi.

--- a/third_party/rust/cc/src/target/llvm.rs
+++ b/third_party/rust/cc/src/target/llvm.rs
@@ -98,6 +98,7 @@
             "llvm" | "softfloat" | "uwp" | "vec-extabi" => "",
             "ilp32" => "_ilp32",
             "abi64" => "",
+            "elfv1" | "elfv2" => "",
             abi => abi,
         };
         Cow::Owned(match (vendor, env, abi) {

[NobodyXu]

That does looks reasonable to me, feel free to open a PR

cc @madsmtm wdyt?

[fossdd]

#1596