Guard gccisms in math.h

[kate]

headers/posix/math.h contains a few non-portable gccsisms. These expand out for various macros. Some have a guard protecting them, for if the macro is already defined.

I propose adding similar guards around the others, so that they made be defined externally, and thus the file will be able to be parsed by a standard C compiler. Like so:

/

@@ -29 +29 @@
 
 #define __HUGE_VALF_v  0x7f800000L
 #define __huge_valf_t  union { unsigned char __c[4]; long __l; float __f; }
-#define HUGE_VALF              (((__huge_valf_t) { __l: __HUGE_VALF_v }).__f)
+#ifndef HUGE_VALF
+#      define HUGE_VALF                (((__huge_valf_t) { __l: __HUGE_VALF_v }).__f)
+#endif
 
 /* TODO: define HUGE_VALL for long doubles */
 

(that's not the only one; it's just an example)

I think they could also be made standard by writing them in the C99 form, {.a = b}, but I don't know if you're targeting C99. If you do, please still add these guards, so the header can be still parsed with a C90 compiler.

[pulkomandy]

R1 will use gcc, this can be delayed.