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 ctan = __ctan
+#pragma weak __ctan = ctan
 
 /* INDENT OFF */
 /*
  * dcomplex ctan(dcomplex z);
  *