d6da428f34
Implement va_list and va_arg for s390x FFI Following the s390x ELF ABI and based on the clang implementation, provide appropriate definitions of va_list in library/core/src/ffi/mod.rs and va_arg handling in compiler/rustc_codegen_llvm/src/va_arg.rs. Fixes the following test cases on s390x: src/test/run-make-fulldeps/c-link-to-rust-va-list-fn src/test/ui/abi/variadic-ffi.rs Fixes https://github.com/rust-lang/rust/issues/84628.