[libc] [llvm] [libc] Add proxy header for fenv.h macro constants. #87863 (PR #87896)

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@@ -12,7 +12,6 @@
 #include "src/__support/FPUtil/FPBits.h"
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lntue wrote:

Add `#include "hdr/fenv_macros.h"` here also. It seems redundant, but it will make the next step easier.

https://github.com/llvm/llvm-project/pull/87896