5261 libm should stop using synonyms.h

*** 28,38 ****
  
          .file   "copysignl.s"
  
  #include "libm.h"
  LIBM_ANSI_PRAGMA_WEAK(copysignl,function)
- #include "libm_synonyms.h"
  
          ENTRY(copysignl)
          movl    12(%esp),%eax           / sign and bexp of x
          movl    24(%esp),%ecx           / sign and bexp of y
          andl    $0x00007fff,%eax        / eax <-- bexp(x)
--- 28,37 ----