Remove unused argument in wasm_runtime_lookup_function and refactor WASMModuleInstance (#3218)

Remove the unused parameter `signature` from `wasm_runtime_lookup_function`.

Refactor the layout of WASMModuleInstance structure:
- move common data members `c_api_func_imports` and `cur_exec_env` from
  `WASMModuleInstanceExtraCommon` to `WASMModuleInstance`
- In `WASMModuleInstance`, enlarge `reserved[3]` to `reserved[5]` in case that
  we need to add more fields in the future

ps.
https://github.com/bytecodealliance/wasm-micro-runtime/issues/2530
https://github.com/bytecodealliance/wasm-micro-runtime/issues/3202

core/iwasm/common/wasm_application.c

@@ -147,10 +147,10 @@ execute_main(WASMModuleInstanceCommon *module_inst, int32 argc, char *argv[])
     }
 #endif /* end of WASM_ENABLE_LIBC_WASI */
 
-    if (!(func = wasm_runtime_lookup_function(module_inst, "main", NULL))
-        && !(func = wasm_runtime_lookup_function(module_inst,
-                                                 "__main_argc_argv", NULL))
-        && !(func = wasm_runtime_lookup_function(module_inst, "_main", NULL))) {
+    if (!(func = wasm_runtime_lookup_function(module_inst, "main"))
+        && !(func =
+                 wasm_runtime_lookup_function(module_inst, "__main_argc_argv"))
+        && !(func = wasm_runtime_lookup_function(module_inst, "_main"))) {
 #if WASM_ENABLE_LIBC_WASI != 0
         wasm_runtime_set_exception(
             module_inst, "lookup the entry point symbol (like _start, main, "
@@ -337,8 +337,7 @@ execute_func(WASMModuleInstanceCommon *module_inst, const char *name,
     bh_assert(argc >= 0);
     LOG_DEBUG("call a function \"%s\" with %d arguments", name, argc);
 
-    if (!(target_func =
-              wasm_runtime_lookup_function(module_inst, name, NULL))) {
+    if (!(target_func = wasm_runtime_lookup_function(module_inst, name))) {
         snprintf(buf, sizeof(buf), "lookup function %s failed", name);
         wasm_runtime_set_exception(module_inst, buf);
         goto fail;

core/iwasm/common/wasm_c_api.c

@@ -4939,19 +4939,17 @@ wasm_instance_new_with_args_ex(wasm_store_t *store, const wasm_module_t *module,
     /* create the c-api func import list */
 #if WASM_ENABLE_INTERP != 0
     if (instance->inst_comm_rt->module_type == Wasm_Module_Bytecode) {
-        WASMModuleInstanceExtra *e =
-            ((WASMModuleInstance *)instance->inst_comm_rt)->e;
-        p_func_imports = &(e->common.c_api_func_imports);
+        WASMModuleInstance *wasm_module_inst =
+            (WASMModuleInstance *)instance->inst_comm_rt;
+        p_func_imports = &(wasm_module_inst->c_api_func_imports);
         import_func_count = MODULE_INTERP(module)->import_function_count;
     }
 #endif
 #if WASM_ENABLE_AOT != 0
     if (instance->inst_comm_rt->module_type == Wasm_Module_AoT) {
-        AOTModuleInstanceExtra *e =
-            (AOTModuleInstanceExtra *)((AOTModuleInstance *)
-                                           instance->inst_comm_rt)
-                ->e;
-        p_func_imports = &(e->common.c_api_func_imports);
+        AOTModuleInstance *aot_module_inst =
+            (AOTModuleInstance *)instance->inst_comm_rt;
+        p_func_imports = &(aot_module_inst->c_api_func_imports);
         import_func_count = MODULE_AOT(module)->import_func_count;
     }
 #endif
@@ -4965,7 +4963,7 @@ wasm_instance_new_with_args_ex(wasm_store_t *store, const wasm_module_t *module,
         goto failed;
     }
 
-    /* fill in module_inst->e->c_api_func_imports */
+    /* fill in module_inst->c_api_func_imports */
     for (i = 0; imports && i < imports->num_elems; i++) {
         wasm_func_t *func_host = NULL;
         wasm_extern_t *in = imports->data[i];

core/iwasm/common/wasm_memory.c

@@ -823,13 +823,11 @@ return_func:
 
 #if WASM_ENABLE_INTERP != 0
         if (module->module_type == Wasm_Module_Bytecode)
-            exec_env =
-                ((WASMModuleInstanceExtra *)module->e)->common.cur_exec_env;
+            exec_env = ((WASMModuleInstance *)module)->cur_exec_env;
 #endif
 #if WASM_ENABLE_AOT != 0
         if (module->module_type == Wasm_Module_AoT)
-            exec_env =
-                ((AOTModuleInstanceExtra *)module->e)->common.cur_exec_env;
+            exec_env = ((AOTModuleInstance *)module)->cur_exec_env;
 #endif
 
         enlarge_memory_error_cb(inc_page_count, total_size_old, 0,

core/iwasm/common/wasm_runtime_common.c

@@ -1853,17 +1853,17 @@ wasm_runtime_get_function_type(const WASMFunctionInstanceCommon *function,
 
 WASMFunctionInstanceCommon *
 wasm_runtime_lookup_function(WASMModuleInstanceCommon *const module_inst,
-                             const char *name, const char *signature)
+                             const char *name)
 {
 #if WASM_ENABLE_INTERP != 0
     if (module_inst->module_type == Wasm_Module_Bytecode)
         return (WASMFunctionInstanceCommon *)wasm_lookup_function(
-            (const WASMModuleInstance *)module_inst, name, signature);
+            (const WASMModuleInstance *)module_inst, name);
 #endif
 #if WASM_ENABLE_AOT != 0
     if (module_inst->module_type == Wasm_Module_AoT)
         return (WASMFunctionInstanceCommon *)aot_lookup_function(
-            (const AOTModuleInstance *)module_inst, name, signature);
+            (const AOTModuleInstance *)module_inst, name);
 #endif
     return NULL;
 }

core/iwasm/common/wasm_runtime_common.h

@@ -611,7 +611,7 @@ wasm_runtime_get_module(WASMModuleInstanceCommon *module_inst);
 /* See wasm_export.h for description */
 WASM_RUNTIME_API_EXTERN WASMFunctionInstanceCommon *
 wasm_runtime_lookup_function(WASMModuleInstanceCommon *const module_inst,
-                             const char *name, const char *signature);
+                             const char *name);
 
 /* Internal API */
 WASMFuncType *