5261 libm should stop using synonyms.h

*** 28,38 ****
  
          .file "fmod.s"
  
  #include "libm.h"
  LIBM_ANSI_PRAGMA_WEAK(fmod,function)
- #include "libm_synonyms.h"
  #include "libm_protos.h"
  
          ENTRY(fmod)
          push    %rbp
          movq    %rsp,%rbp
--- 28,37 ----