LibWeb: Add IDL integer typedefs

To make it easier to work out what the correctly sized type should be,
instead of needing to consult the spec or IDL generator.

Userland/Libraries/LibWeb/WebIDL/Types.h

@@ -0,0 +1,45 @@
+/*
+ * Copyright (c) 2023, Shannon Booth <shannon@serenityos.org>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#pragma once
+
+#include <AK/Types.h>
+
+namespace Web::WebIDL {
+
+// https://webidl.spec.whatwg.org/#idl-byte
+// The byte type is a signed integer type that has values in the range [−128, 127].
+using Byte = i8;
+
+// https://webidl.spec.whatwg.org/#idl-octet
+// The octet type is an unsigned integer type that has values in the range [0, 255].
+using Octet = u8;
+
+// https://webidl.spec.whatwg.org/#idl-short
+// The short type is a signed integer type that has values in the range [−32768, 32767].
+using Short = i16;
+
+// https://webidl.spec.whatwg.org/#idl-unsigned-short
+// The unsigned short type is an unsigned integer type that has values in the range [0, 65535].
+using UnsignedShort = u16;
+
+// https://webidl.spec.whatwg.org/#idl-long
+// The long type is a signed integer type that has values in the range [−2147483648, 2147483647].
+using Long = i32;
+
+// https://webidl.spec.whatwg.org/#idl-unsigned-long
+// The unsigned long type is an unsigned integer type that has values in the range [0, 4294967295].
+using UnsignedLong = u32;
+
+// https://webidl.spec.whatwg.org/#idl-long-long
+// The long long type is a signed integer type that has values in the range [−9223372036854775808, 9223372036854775807].
+using LongLong = i64;
+
+// https://webidl.spec.whatwg.org/#idl-unsigned-long-long
+// The unsigned long long type is an unsigned integer type that has values in the range [0, 18446744073709551615].
+using UnsignedLongLong = u64;
+
+}