Change WASM_ANYREF to WASM_EXTERNREF (#3426)

wasm-c-api wasm.h had changed WASM_ANYREF to WASM_EXTERNREF,
we had better change it in WAMR also:
2ce1367c9d/include/wasm.h (L185)

samples/wasm-c-api/src/callback.c

@@ -22,7 +22,7 @@ void wasm_val_print(wasm_val_t val) {
     case WASM_F64: {
       printf("%g", val.of.f64);
     } break;
-    case WASM_ANYREF:
+    case WASM_EXTERNREF:
     case WASM_FUNCREF: {
       if (val.of.ref == NULL) {
         printf("null");

samples/wasm-c-api/src/hostref.c

@@ -193,7 +193,7 @@ int main(int argc, const char* argv[]) {
   // Create external callback function.
   printf("Creating callback...\n");
   own wasm_functype_t* callback_type = wasm_functype_new_1_1(
-    wasm_valtype_new(WASM_ANYREF), wasm_valtype_new(WASM_ANYREF));
+    wasm_valtype_new(WASM_EXTERNREF), wasm_valtype_new(WASM_EXTERNREF));
   own wasm_func_t* callback_func =
     wasm_func_new(store, callback_type, callback);
 
@@ -245,7 +245,7 @@ int main(int argc, const char* argv[]) {
   wasm_ref_delete(host2_cp);
 
   own wasm_val_t val;
-  val.kind = WASM_ANYREF;
+  val.kind = WASM_EXTERNREF;
   val.of.ref = wasm_ref_copy(host1);
   wasm_ref_t *ref_cp = wasm_ref_copy(val.of.ref);
   check(ref_cp, host1);
@@ -264,12 +264,12 @@ int main(int argc, const char* argv[]) {
   check(call_v_r(global_get), NULL);
 
   wasm_global_get(global, &val);
-  assert(val.kind == WASM_ANYREF);
+  assert(val.kind == WASM_EXTERNREF);
   assert(val.of.ref == NULL);
   val.of.ref = host2;
   wasm_global_set(global, &val);
   wasm_global_get(global, &val);
-  assert(val.kind == WASM_ANYREF);
+  assert(val.kind == WASM_EXTERNREF);
   assert(val.of.ref == host2);
 
   printf("Accessing table...\n");

samples/wasm-c-api/src/reflect.c

@@ -30,7 +30,7 @@ void print_valtype(const wasm_valtype_t* type) {
     case WASM_F32: printf("f32"); break;
     case WASM_F64: printf("f64"); break;
     case WASM_V128: printf("v128"); break;
-    case WASM_ANYREF: printf("anyref"); break;
+    case WASM_EXTERNREF: printf("externref"); break;
     case WASM_FUNCREF: printf("funcref"); break;
   }
 }