Specialize fdlibm to jerry

Keep IEEE code paths only:
* removed SVID, XOPEN, POSIX code paths from everywhere.
* deleted s_lib_version.c, as version is only useful if multiple
  standards are supported.
* deleted k_standard.c, as it handles non-IEEE exception cases only.
* renamed the e_{acos,asin,atan2,exp,fmod,log,pow,sqrt}.c sources as
  s_.*, dropped the __ieee754_ prefix from the names of the
  appropriate functions therein, and deleted the
  w_{acos,asin,atan2,exp,fmod,log,pow,sqrt}.c wrapper code.

Keep C99 declaration variants only:
* removed old C-style function declaration variants.
* removed data declaration variants where const qualifier was not
  used.

Clean unused sources/functions:
* removed s_{rint,significand,tanh}.c and the appropriate functions
  defined therein.

JerryScript-DCO-1.0-Signed-off-by: Akos Kiss akiss@inf.u-szeged.hu

third-party/fdlibm/s_finite.c

@@ -18,14 +18,9 @@
 
 #include "fdlibm.h"
 
-#ifdef __STDC__
-	int finite(double x)
-#else
-	int finite(x)
-	double x;
-#endif
+int finite(double x)
 {
-	int hx; 
+	int hx;
 	hx = __HI(x);
 	return  (unsigned)((hx&0x7fffffff)-0x7ff00000)>>31;
 }