LibWeb: Add WebAssembly.Global and exports support for global instances

Author: https://github.com/ADKaster
Commit: 44e3817219
Pull-request: https://github.com/LadybirdBrowser/ladybird/pull/3028

Libraries/LibWeb/WebAssembly/Global.h

@@ -0,0 +1,43 @@
+/*
+ * Copyright (c) 2024, Andrew Kaster <andrew@ladybird.org>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#pragma once
+
+#include <LibWasm/AbstractMachine/AbstractMachine.h>
+#include <LibWeb/Bindings/ExceptionOrUtils.h>
+#include <LibWeb/Bindings/GlobalPrototype.h>
+#include <LibWeb/Bindings/PlatformObject.h>
+
+namespace Web::WebAssembly {
+
+struct GlobalDescriptor {
+    Bindings::ValueType value;
+    bool mutable_ { false };
+};
+
+class Global : public Bindings::PlatformObject {
+    WEB_PLATFORM_OBJECT(Global, Bindings::PlatformObject);
+    GC_DECLARE_ALLOCATOR(Global);
+
+public:
+    static WebIDL::ExceptionOr<GC::Ref<Global>> construct_impl(JS::Realm&, GlobalDescriptor& descriptor, JS::Value v);
+
+    WebIDL::ExceptionOr<JS::Value> value_of() const;
+
+    WebIDL::ExceptionOr<void> set_value(JS::Value);
+    WebIDL::ExceptionOr<JS::Value> value() const;
+
+    Wasm::GlobalAddress address() const { return m_address; }
+
+private:
+    Global(JS::Realm&, Wasm::GlobalAddress);
+
+    virtual void initialize(JS::Realm&) override;
+
+    Wasm::GlobalAddress m_address;
+};
+
+}