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 truncf = __truncf
+#pragma weak __truncf = truncf
 
 #include "libm.h"
 
 float
 truncf(float x) {