Re-style fdlibm to conform to jerry guidelines

* First re-style was done automatically by indent to minimize the
  chance of errors during rewrite.

* Manual changes were applied to non-critical places only (comments
  and spaces):
  * Replaced all tabs with spaces.
  * Fixed tab stops in formulae in function comments.
    (Note: ASCII art for math formulae (especially for super- and
    subscripts) is a terrible idea.)
  * Unified the style of function comments.
  * Moved some in-code comments to their right places, which indent
    couldn't handle.
  * Added spaces to formulae of in-code comments to make them more
    readable.
  * Added braces mandated by jerry style guidelines.
  * Added parentheses to multiline #ifdef.

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

third-party/fdlibm/s_isnan.c

@@ -6,24 +6,25 @@
  *
  * Developed at SunSoft, a Sun Microsystems, Inc. business.
  * Permission to use, copy, modify, and distribute this
- * software is freely granted, provided that this notice 
+ * software is freely granted, provided that this notice
  * is preserved.
  * ====================================================
  */
 
-/*
- * isnan(x) returns 1 is x is nan, else 0;
+/* isnan(x) returns 1 is x is nan, else 0;
  * no branching!
  */
 
 #include "fdlibm.h"
 
-int isnan(double x)
+int
+isnan (double x)
 {
-	int hx,lx;
-	hx = (__HI(x)&0x7fffffff);
-	lx = __LO(x);
-	hx |= (unsigned)(lx|(-lx))>>31;
-	hx = 0x7ff00000 - hx;
-	return ((unsigned)(hx))>>31;
-}
+  int hx, lx;
+
+  hx = (__HI (x) & 0x7fffffff);
+  lx = __LO (x);
+  hx |= (unsigned) (lx | (-lx)) >> 31;
+  hx = 0x7ff00000 - hx;
+  return ((unsigned) (hx)) >> 31;
+} /* isnan */