[wasm] Add UTF-8 validation

src/wasm/wasm-module.cc

Index: src/wasm/wasm-module.cc
diff --git a/src/wasm/wasm-module.cc b/src/wasm/wasm-module.cc
index 9ec439d4b5192229dea9573907e2236830cc3135..55bb7d973cf297f3a23da000fb6c135a5462174a 100644
--- a/src/wasm/wasm-module.cc
+++ b/src/wasm/wasm-module.cc
@@ -553,9 +553,9 @@ MaybeHandle<JSObject> WasmModule::Instantiate(Isolate* isolate,
 
       WasmName str = GetName(func.name_offset, func.name_length);
       WasmName str_null = {nullptr, 0};
-      Handle<String> name = factory->InternalizeUtf8String(str);
       Handle<Code> code = Handle<Code>::null();
       Handle<JSFunction> function = Handle<JSFunction>::null();
+      Handle<String> functionName;
       if (func.external) {
         // Lookup external function in FFI object.
         MaybeHandle<JSFunction> function =
@@ -578,8 +578,9 @@ MaybeHandle<JSObject> WasmModule::Instantiate(Isolate* isolate,
           return MaybeHandle<JSObject>();
         }
         if (func.exported) {
+          functionName = factory->InternalizeUtf8String(str);
           function = compiler::CompileJSToWasmWrapper(
-              isolate, &module_env, name, code, instance.js_object, i);
+              isolate, &module_env, functionName, code, instance.js_object, i);
           record_code_size(function->code());
         }
       }
@@ -589,12 +590,13 @@ MaybeHandle<JSObject> WasmModule::Instantiate(Isolate* isolate,
         code_table->set(i, *code);
         record_code_size(*code);
       }
-      if (func.exported) {
+      if (!function.is_null()) {
         // Exported functions are installed as read-only properties on the
         // module.
         desc.set_value(function);
         Maybe<bool> status = JSReceiver::DefineOwnProperty(
-            isolate, instance.js_object, name, &desc, Object::THROW_ON_ERROR);
+            isolate, instance.js_object, functionName, &desc,
+            Object::THROW_ON_ERROR);
         if (!status.IsJust())
           thrower.Error("export of %.*s failed.", str.length(), str.start());
       }