Auto merge of rust-lang#61881 - glaubitz:sparc64-ffi-abi, r=petrochenkov

librustc_codegen_llvm: Use repr(transparent) for bitflags over repr(C…

…) (rust-lang#61306)

In order to make sure that Rust's bitflags types are passed the same way in the Rust ABI as they are in the C ABI, we need to use the attribute repr(transparent) over the repr(C) attribute for the single-field bitflags structs in in order to prevent ABI mismatches. Thanks to Michael Karcher for finding this bug.

Author: bors

src/librustc_codegen_llvm/llvm/ffi.rs

@@ -564,7 +564,7 @@ pub mod debuginfo {
 
     // These values **must** match with LLVMRustDIFlags!!
     bitflags! {
-        #[repr(C)]
+        #[repr(transparent)]
         #[derive(Default)]
         pub struct DIFlags: ::libc::uint32_t {
             const FlagZero                = 0;
@@ -593,7 +593,7 @@ pub mod debuginfo {
 
     // These values **must** match with LLVMRustDISPFlags!!
     bitflags! {
-        #[repr(C)]
+        #[repr(transparent)]
         #[derive(Default)]
         pub struct DISPFlags: ::libc::uint32_t {
             const SPFlagZero              = 0;