5261 libm should stop using synonyms.h

@@ -65,11 +65,11 @@
  * Only decimal values are given. We assume that the compiler will convert
  * from decimal to binary accurately enough to produce the correct
  * hexadecimal values.
  */
 
-#pragma weak expl = __expl
+#pragma weak __expl = expl
 
 #include "libm.h"
 
 extern const long double _TBL_expl_hi[], _TBL_expl_lo[];