Implement the segue optimization for LLVM AOT/JIT (#2230)

Segue is an optimization technology which uses x86 segment register to store
the WebAssembly linear memory base address, so as to remove most of the cost
of SFI (Software-based Fault Isolation) base addition and free up a general
purpose register, by this way it may:
- Improve the performance of JIT/AOT
- Reduce the footprint of JIT/AOT, the JIT/AOT code generated is smaller
- Reduce the compilation time of JIT/AOT

This PR uses the x86-64 GS segment register to apply the optimization, currently
it supports linux and linux-sgx platforms on x86-64 target. By default it is disabled,
developer can use the option below to enable it for wamrc and iwasm(with LLVM
JIT enabled):
```bash
wamrc --enable-segue=[<flags>] -o output_file wasm_file
iwasm --enable-segue=[<flags>] wasm_file [args...]
```
`flags` can be:
    i32.load, i64.load, f32.load, f64.load, v128.load,
    i32.store, i64.store, f32.store, f64.store, v128.store
Use comma to separate them, e.g. `--enable-segue=i32.load,i64.store`,
and `--enable-segue` means all flags are added.

Acknowledgement:
Many thanks to Intel Labs, UC San Diego and UT Austin teams for introducing this
technology and the great support and guidance!

Signed-off-by: Wenyong Huang <wenyong.huang@intel.com>
Co-authored-by: Vahldiek-oberwagner, Anjo Lucas <anjo.lucas.vahldiek-oberwagner@intel.com>

core/shared/platform/linux/platform_internal.h

@@ -63,6 +63,20 @@ typedef sem_t korp_sem;
 
 #define bh_socket_t int
 
+#if defined(BUILD_TARGET_X86_64) || defined(BUILD_TARGET_AMD_64)
+#define os_writegsbase(base_addr)                                 \
+    do {                                                          \
+        uint64 __gs_value = (uint64)(uintptr_t)base_addr;         \
+        asm volatile("wrgsbase %0" ::"r"(__gs_value) : "memory"); \
+    } while (0)
+#if 0
+/* _writegsbase_u64 also works, but need to add -mfsgsbase flag for gcc */
+#include <immintrin.h>
+#define os_writegsbase(base_addr) \
+    _writegsbase_u64(((uint64)(uintptr_t)base_addr))
+#endif
+#endif
+
 #if WASM_DISABLE_HW_BOUND_CHECK == 0
 #if defined(BUILD_TARGET_X86_64) || defined(BUILD_TARGET_AMD_64)            \
     || defined(BUILD_TARGET_AARCH64) || defined(BUILD_TARGET_RISCV64_LP64D) \