Avoids a compile error from start.zig:

	/home/kivikakk/zig/build/lib/zig/std/start.zig:265:28: error:
	expected type 'u8', found 'i8'
			    return result;
				   ^
	/home/kivikakk/zig/build/lib/zig/std/start.zig:265:28: note:
	unsigned 8-bit int cannot represent all possible signed 8-bit
	values
			    return result;