5261 libm should stop using synonyms.h

@@ -37,11 +37,10 @@
  * nearbyint(x) is x unchanged if x is +/-0 or +/-inf.  If x is NaN,
  * nearbyint(x) is also NaN.
  */
 
 #include "libm.h"
-#include "fenv_synonyms.h"
 #include <fenv.h>
 
 double
 __nearbyint(double x) {
         union {