5261 libm should stop using synonyms.h

@@ -25,12 +25,12 @@
 /*
  * Copyright 2006 Sun Microsystems, Inc.  All rights reserved.
  * Use is subject to license terms.
  */
 
-#pragma weak isnanf = __isnanf
-#pragma weak _isnanf = __isnanf
+#pragma weak __isnanf = isnanf
+#pragma weak _isnanf = isnanf
 
 #include "libm.h"
 
 int
 isnanf(float x) {