5261 libm should stop using synonyms.h

@@ -24,11 +24,11 @@
 /*
  * Copyright 2006 Sun Microsystems, Inc.  All rights reserved.
  * Use is subject to license terms.
  */
 
-#pragma weak rint = __rint
+#pragma weak __rint = rint
 
 /*
  * rint(x) return x rounded to integral according to the rounding direction
  * rint(x) returns result with the same sign as x's,  including 0.0.
  */