Add flag -w to rgbasm to disable warnings

A lot of warnings are being added (and more will come) so it makes sense
to be able to disable them in legacy source that generates warnings but
is otherwise correct.

Signed-off-by: AntonioND <[email protected]>

include/asm/main.h

@@ -11,6 +11,7 @@ struct sOptions {
 	bool verbose;
 	bool haltnop;
 	bool exportall;
+	bool warnings; /* true to enable warnings, false to disable them. */
 	    //-1 == random
 };