Add more fast jit fixed virtual regs (#1409)

Add fast jit fixed virtual register import_func_ptrs_reg and func_type_indexes_reg
for the preparation of further optimizations.

core/iwasm/interpreter/wasm_runtime.h

@@ -191,6 +191,7 @@ struct WASMModuleInstance {
 #if WASM_ENABLE_FAST_JIT != 0
     /* point to JITed functions */
     void **fast_jit_func_ptrs;
+    uint32 *func_type_indexes;
 #endif
 
     WASMMemoryInstance **memories;