Make Error.prototype.toString spec compliant; and fix various side-effect-free error printing metho…

test/cctest/test-api.cc

Index: test/cctest/test-api.cc
diff --git a/test/cctest/test-api.cc b/test/cctest/test-api.cc
index bd26f9277b4ad4d5142ad6e8daf65e5f264b582a..c5171e8cbf260e057da06dbd0fd3580d5f13db98 100644
--- a/test/cctest/test-api.cc
+++ b/test/cctest/test-api.cc
@@ -5612,7 +5612,7 @@ TEST(APIThrowMessageOverwrittenToString) {
 
 static void check_custom_error_tostring(v8::Local<v8::Message> message,
                                         v8::Local<v8::Value> data) {
-  const char* uncaught_error = "Uncaught MyError toString";
+  const char* uncaught_error = "Uncaught my name: my message";
   CHECK(message->Get()
             ->Equals(CcTest::isolate()->GetCurrentContext(),
                      v8_str(uncaught_error))
@@ -5630,9 +5630,6 @@ TEST(CustomErrorToString) {
       "  this.message = message;                           "
       "}                                                   "
       "MyError.prototype = Object.create(Error.prototype); "
-      "MyError.prototype.toString = function() {           "
-      "  return 'MyError toString';                        "
-      "};                                                  "
       "throw new MyError('my name', 'my message');         ");
   context->GetIsolate()->RemoveMessageListeners(check_custom_error_tostring);
 }
@@ -5694,7 +5691,7 @@ TEST(CustomErrorMessage) {
 
 static void check_custom_rethrowing_message(v8::Local<v8::Message> message,
                                             v8::Local<v8::Value> data) {
-  const char* uncaught_error = "Uncaught exception";
+  const char* uncaught_error = "Uncaught [object Object]";
   CHECK(message->Get()
             ->Equals(CcTest::isolate()->GetCurrentContext(),
                      v8_str(uncaught_error))