5261 libm should stop using synonyms.h

@@ -54,11 +54,11 @@
  * The decimal values may be used, provided that the compiler will convert
  * from decimal to binary accurately enough to produce the hexadecimal values
  * shown.
  */
 
-#pragma weak atan2l = __atan2l
+#pragma weak __atan2l = atan2l
 
 #include "libm.h"
 #include "longdouble.h"
 
 static const long double