5261 libm should stop using synonyms.h

@@ -28,11 +28,10 @@
 
         .file "atan2f.s"
 
 #include "libm.h"
 LIBM_ANSI_PRAGMA_WEAK(atan2f,function)
-#include "libm_synonyms.h"
 #include "libm_protos.h"
 
         ENTRY(atan2f)
         flds    4(%esp)                 / push y
         flds    8(%esp)                 / push x