Fix to solaris build problem re quiet_nan

It appears that the logic is already in the code,
just that the NANARG determined in mconf.h was not
used to declare the local quiet_nan version.

Basic/Math/quiet_nan.c

@@ -1,6 +1,6 @@
 #include "mconf.h"
 /* Patch NaN function where no system NaN is available */
-double quiet_nan(void)
+double quiet_nan(NANARG)
 {
 #ifdef NaN
   double a;