[clang] [clang-tools-extra] [llvm] [clang][headers] Need a way for math.h to share the definitions of INIFINITY and NAN with float.h (PR #164348)

[Ian Anderson via cfe-commits]

================
@@ -7,13 +7,21 @@
  *===-----------------------------------------------------------------------===
  */
 
-#ifndef __CLANG_FLOAT_H
-#define __CLANG_FLOAT_H
-
 #if defined(__MVS__) && __has_include_next(<float.h>)
+#include <__float_header_macro.h>
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ian-twilightcoder wrote:

It's defined on line 21 if you just include <float.h> with no `__need`.

https://github.com/llvm/llvm-project/pull/164348