Implement GC (Garbage Collection) feature for interpreter, AOT and LLVM-JIT (#3125)

Implement the GC (Garbage Collection) feature for interpreter mode,
AOT mode and LLVM-JIT mode, and support most features of the latest
spec proposal, and also enable the stringref feature.

Use `cmake -DWAMR_BUILD_GC=1/0` to enable/disable the feature,
and `wamrc --enable-gc` to generate the AOT file with GC supported.

And update the AOT file version from 2 to 3 since there are many AOT
ABI breaks, including the changes of AOT file format, the changes of
AOT module/memory instance layouts, the AOT runtime APIs for the
AOT code to invoke and so on.

core/iwasm/include/aot_comp_option.h

@@ -0,0 +1,46 @@
+/*
+ * Copyright (C) 2019 Intel Corporation. All rights reserved.
+ * SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+ */
+
+#ifndef __AOT_COMP_OPTION_H__
+#define __AOT_COMP_OPTION_H__
+
+typedef struct AOTCompOption {
+    bool is_jit_mode;
+    bool is_indirect_mode;
+    char *target_arch;
+    char *target_abi;
+    char *target_cpu;
+    char *cpu_features;
+    bool is_sgx_platform;
+    bool enable_bulk_memory;
+    bool enable_thread_mgr;
+    bool enable_tail_call;
+    bool enable_simd;
+    bool enable_ref_types;
+    bool enable_gc;
+    bool enable_aux_stack_check;
+    bool enable_aux_stack_frame;
+    bool enable_perf_profiling;
+    bool enable_memory_profiling;
+    bool disable_llvm_intrinsics;
+    bool disable_llvm_lto;
+    bool enable_llvm_pgo;
+    bool enable_stack_estimation;
+    bool quick_invoke_c_api_import;
+    char *use_prof_file;
+    uint32_t opt_level;
+    uint32_t size_level;
+    uint32_t output_format;
+    uint32_t bounds_checks;
+    uint32_t stack_bounds_checks;
+    uint32_t segue_flags;
+    char **custom_sections;
+    uint32_t custom_sections_count;
+    const char *stack_usage_file;
+    const char *llvm_passes;
+    const char *builtin_intrinsics;
+} AOTCompOption, *aot_comp_option_t;
+
+#endif