Fix call to selectSymbol in std.os.windows.user32.messageBoxW

[Manuzor]

Arguments to selectSymbol were passed in the wrong order. It expects the static function pointer as first argument.

zig/lib/std/os/windows/user32.zig

Lines 15 to 22 in a38042e

	fn selectSymbol(comptime function_static: anytype, function_dynamic: @TypeOf(function_static), comptime os: std.Target.Os.WindowsVersion) @TypeOf(function_static) {
	comptime {
	const sym_ok = builtin.Target.current.os.isAtLeast(.windows, os);
	if (sym_ok == true) return function_static;
	if (sym_ok == null) return function_dynamic;
	if (sym_ok == false) @compileError("Target OS range does not support function, at least " ++ @tagName(os) ++ " is required");
	}
	}

[Manuzor]

I'm not sure how my change could've caused the azure pipelines check to fail. I assume it's not on my end? Especially since the Mac OS cmake step has failed but I only touched windows specific stuff in the std lib.

[andrewrk]

You just happened to open the PR when the CI was broken due to llvm12 upgrade. Not your fault! Thanks for the fix. I want to mention however #4426 in which we will likely end up removing user32.dll extern decls from std lib altogether.