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.h

@@ -0,0 +1,84 @@
+/*
+ * Copyright (C) 2021 Intel Corporation.  All rights reserved.
+ * SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+ */
+
+#ifndef _JIT_CODEGEN_H_
+#define _JIT_CODEGEN_H_
+
+#include "bh_platform.h"
+#include "jit_compiler.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/**
+ * Initialize codegen module, such as instruction encoder.
+ *
+ * @return true if succeeded; false if failed.
+ */
+bool
+jit_codegen_init();
+
+/**
+ * Destroy codegen module, such as instruction encoder.
+ */
+void
+jit_codegen_destroy();
+
+/**
+ * Get hard register information of each kind.
+ *
+ * @return the JitHardRegInfo array of each kind
+ */
+const JitHardRegInfo *
+jit_codegen_get_hreg_info();
+
+/**
+ * Get hard register by name.
+ *
+ * @param name the name of the hard register
+ *
+ * @return the hard register of the name
+ */
+JitReg
+jit_codegen_get_hreg_by_name(const char *name);
+
+/**
+ * Generate native code for the given compilation context
+ *
+ * @param cc the compilation context that is ready to do codegen
+ *
+ * @return true if succeeds, false otherwise
+ */
+bool
+jit_codegen_gen_native(JitCompContext *cc);
+
+/**
+ * lower unsupported operations to supported ones for the target.
+ *
+ * @param cc the compilation context that is ready to do codegen
+ *
+ * @return true if succeeds, false otherwise
+ */
+bool
+jit_codegen_lower(JitCompContext *cc);
+
+/**
+ * Dump native code in the given range to assembly.
+ *
+ * @param begin_addr begin address of the native code
+ * @param end_addr end address of the native code
+ */
+void
+jit_codegen_dump_native(void *begin_addr, void *end_addr);
+
+int
+jit_codegen_interp_jitted_glue(void *self, JitInterpSwitchInfo *info, void *pc);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* end of _JIT_CODEGEN_H_ */