5261 libm should stop using synonyms.h

@@ -25,11 +25,11 @@
 /*
  * Copyright 2006 Sun Microsystems, Inc.  All rights reserved.
  * Use is subject to license terms.
  */
 
-#pragma weak exp2f = __exp2f
+#pragma weak __exp2f = exp2f
 
 #include "libm.h"
 
 float
 exp2f(float x) {