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 cosh = __cosh
+#pragma weak __cosh = cosh
 
 /* INDENT OFF */
 /*
  * cosh(x)
  * Code originated from 4.3bsd.