5261 libm should stop using synonyms.h

@@ -28,11 +28,10 @@
 
         .file   "atan.s"
 
 #include "libm.h"
 LIBM_ANSI_PRAGMA_WEAK(atan,function)
-#include "libm_synonyms.h"
 
         ENTRY(atan)
         fldl    4(%esp)                 / push arg
         fld1                            / push 1.0
         fpatan                          / atan(arg/1.0)