[libc-commits] [libc] [libc] Fix ucontext_t and mcontext_t for C compliance (PR #192648)

[Schrodinger ZHU Yifan via libc-commits]

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@@ -34,7 +34,7 @@ typedef struct alignas(16) ucontext_t {
   // provide space here for the FP state, and the pointer in uc_mcontext
   // can be set to point here. 64 long ints provide 512 bytes, which is
   // the size required for FXSAVE.
-  alignas(16) long int __fpregs_mem[64];
+  _Alignas(16) long int __fpregs_mem[64];
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SchrodingerZhu wrote:

This will be rejected by GCC on C++ mode
```
https://godbolt.org/z/bEzM65EoY
```

https://github.com/llvm/llvm-project/pull/192648