5261 libm should stop using synonyms.h

*** 28,38 ****
  
          .file "log10f.s"
  
  #include "libm.h"
  LIBM_ANSI_PRAGMA_WEAK(log10f,function)
- #include "libm_synonyms.h"
  #include "libm_protos.h"
  
          ENTRY(log10f)
          fldlg2  
          flds    4(%esp)                 / st = arg, st(1) = log10(2)
--- 28,37 ----