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

[via llvm-commits]

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@@ -17,10 +17,10 @@
 #endif
 
 #include <arm_acle.h>
-#include <fenv.h>
 #include <stdint.h>
 
 #include "src/__support/FPUtil/FPBits.h"
+#include <fenv.h>
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lntue wrote:

Keep `#include <fenv.h>` in where it was, and 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