5261 libm should stop using synonyms.h

@@ -57,11 +57,11 @@
  *
  * Accuracy:
  *      computer TRIG(x) returns trig(x) nearly rounded.
  */
 
-#pragma weak cosl = __cosl
+#pragma weak __cosl = cosl
 
 #include "libm.h"
 #include "longdouble.h"
 
 long double