[wasm] Differentiate unnamed and empty names

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 e7c0a02f9ea1061a3c9e683a91510adc4174dabe..1b5bb27cdf1e5e0c2b31fa6f9eec6235f68a1d41 100644
--- a/src/wasm/wasm-module.cc
+++ b/src/wasm/wasm-module.cc
@@ -340,7 +340,7 @@ static MaybeHandle<JSFunction> ReportFFIError(ErrorThrower& thrower,
                                               const char* error, uint32_t index,
                                               wasm::WasmName module_name,
                                               wasm::WasmName function_name) {
-  if (function_name.start()) {
+  if (!function_name.is_empty()) {
     thrower.Error("Import #%d module=\"%.*s\" function=\"%.*s\" error: %s",
                   index, module_name.length(), module_name.start(),
                   function_name.length(), function_name.start(), error);
@@ -376,7 +376,7 @@ static MaybeHandle<JSFunction> LookupFunction(
   }
 
   Handle<Object> function;
-  if (function_name.start()) {
+  if (!function_name.is_empty()) {
     // Look up the function in the module.
     Handle<String> name = factory->InternalizeUtf8String(function_name);
     MaybeHandle<Object> result = Object::GetProperty(module, name);