driver: implement post-target run argv semantics

cmd/ww/main.c

@@ -7849,14 +7849,11 @@ parse_build_flags(const char *cmd, int argc, char **argv,
 			return -1;
 		} else if (*src_out == NULL) {
 			*src_out = argv[i];
-			/* Go's FlagSet stops at the first positional. For build,
-			 * everything after it is package-request input, even "--". */
-			if (strcmp(cmd, "build") == 0) {
-				i++;
-				break;
-			}
-		} else {
-			break;	/* leave remaining argv to caller (run-args) */
+			/* Go's FlagSet stops at the first positional.  Build leaves
+			 * the suffix as package-request input; run passes it verbatim
+			 * to the selected program, including flag-like operands. */
+			i++;
+			break;
 		}
 	}
 	return i;