5261 libm should stop using synonyms.h

*** 28,38 ****
  
          .file   "copysign.S"
  
  #include "libm.h"
  LIBM_ANSI_PRAGMA_WEAK(copysign,function)
- #include "libm_synonyms.h"
  
          ENTRY(copysign)
          sethi   %hi(0x80000000),%o3
          andn    %o0,%o3,%o0
          and     %o2,%o3,%o2
--- 28,37 ----