LibWasm: Add basic support for module instantiation and execution stubs

This adds very basic support for module instantiation/allocation, as
well as a stub for an interpreter (and executions APIs).
The 'wasm' utility is further expanded to instantiate, and attempt
executing the first non-imported function in the module.
Note that as the execution is a stub, the expected result is a zero.
Regardless, this will allow future commits to implement the JS
WebAssembly API. :^)

Userland/Libraries/LibWasm/AbstractMachine/Interpreter.cpp

@@ -0,0 +1,23 @@
+/*
+ * Copyright (c) 2021, Ali Mohammad Pur <mpfard@serenityos.org>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#include <LibWasm/AbstractMachine/AbstractMachine.h>
+#include <LibWasm/AbstractMachine/Configuration.h>
+#include <LibWasm/AbstractMachine/Interpreter.h>
+#include <LibWasm/Opcode.h>
+
+namespace Wasm {
+
+void Interpreter::interpret(Configuration& configuration)
+{
+    // FIXME: Interpret stuff
+    dbgln("FIXME: Interpret stuff!");
+    // Push some dummy values
+    for (size_t i = 0; i < configuration.frame()->arity(); ++i)
+        configuration.stack().push(make<Value>(0));
+}
+
+}