5261 libm should stop using synonyms.h

@@ -24,12 +24,10 @@
 /*
  * Copyright 2005 Sun Microsystems, Inc.  All rights reserved.
  * Use is subject to license terms.
  */
 
-#pragma weak atan2pi = __atan2pi
-
 /*
  * atan2pi(x) = atan2(x)/pi
  */
 
 #include "libm.h"