Import WAMR Fast JIT (#1343)

Import WAMR Fast JIT which is a lightweight JIT with quick startup, small footprint,
relatively good performance (~40% to ~50% of LLVM JIT) and good portability.

Platforms supported: Linux, MacOS and Linux SGX.
Arch supported: x86-64.

core/iwasm/fast-jit/jit_codegen.c

@@ -0,0 +1,22 @@
+/*
+ * Copyright (C) 2021 Intel Corporation.  All rights reserved.
+ * SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+ */
+
+#include "jit_compiler.h"
+#include "jit_codegen.h"
+
+bool
+jit_pass_lower_cg(JitCompContext *cc)
+{
+    return jit_codegen_lower(cc);
+}
+
+bool
+jit_pass_codegen(JitCompContext *cc)
+{
+    if (!jit_annl_enable_jitted_addr(cc))
+        return false;
+
+    return jit_codegen_gen_native(cc);
+}