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_sin.c

@@ -20,8 +20,8 @@
  *	__ieee754_rem_pio2	... argument reduction routine
  *
  * Method.
- *      Let S,C and T denote the sin, cos and tan respectively on 
- *	[-PI/4, +PI/4]. Reduce the argument x to y1+y2 = x-k*pi/2 
+ *      Let S,C and T denote the sin, cos and tan respectively on
+ *	[-PI/4, +PI/4]. Reduce the argument x to y1+y2 = x-k*pi/2
  *	in [-pi/4 , +pi/4], and let n = k mod 4.
  *	We have
  *
@@ -39,17 +39,12 @@
  *      trig(NaN)    is that NaN;
  *
  * Accuracy:
- *	TRIG(x) returns trig(x) nearly rounded 
+ *	TRIG(x) returns trig(x) nearly rounded
  */
 
 #include "fdlibm.h"
 
-#ifdef __STDC__
-	double sin(double x)
-#else
-	double sin(x)
-	double x;
-#endif
+double sin(double x)
 {
 	double y[2],z=0.0;
 	int n, ix;