scanner: Generate 'since' macros for requests as well

We already generate WL_[INTERFACE]_[REQUEST]_SINCE_VERSION macros for
events in the server protocol headers. Lets do the same for requests in
the client protocol headers as well.

Signed-off-by: Jonas Ådahl <jadahl@gmail.com>
Reviewed-by: David FORT <contact@hardening-consulting.com>
Reviewed-by: Daniel Stone <daniels@collabora.com>

src/scanner.c

@@ -1270,6 +1270,7 @@ emit_header(struct protocol *protocol, enum side side)
 		} else {
 			emit_structs(&i->event_list, i, side);
 			emit_opcodes(&i->request_list, i);
+			emit_opcode_versions(&i->request_list, i);
 			emit_stubs(&i->request_list, i);
 		}