5261 libm should stop using synonyms.h

@@ -24,11 +24,11 @@
 /*
  * Copyright 2005 Sun Microsystems, Inc.  All rights reserved.
  * Use is subject to license terms.
  */
 
-#pragma weak cosf = __cosf
+#pragma weak __cosf = cosf
 
 /*
  * See sincosf.c
  */