[esnext] implement frontend changes for async/await proposal

src/messages.h

 // Copyright 2006-2008 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // The infrastructure used for (localized) message reporting in V8.
 //
 // Note: there's a big unresolved issue about ownership of the data
 // structures used by this framework.
 
 #ifndef V8_MESSAGES_H_
@@ skipping 340 matching lines @@
   T(ToRadixFormatRange, "toString() radix argument must be between 2 and 36")  \
   T(TypedArraySetNegativeOffset, "Start offset is negative")                   \
   T(TypedArraySetSourceTooLarge, "Source is too large")                        \
   T(UnsupportedTimeZone, "Unsupported time zone specified %")                  \
   T(ValueOutOfRange, "Value % out of range for % options property %")          \
   /* SyntaxError */                                                            \
   T(BadGetterArity, "Getter must not have any formal parameters.")             \
   T(BadSetterArity, "Setter must have exactly one formal parameter.")          \
   T(ConstructorIsAccessor, "Class constructor may not be an accessor")         \
   T(ConstructorIsGenerator, "Class constructor may not be a generator")        \
+  T(ConstructorIsAsync, "Class constructor may not be an async method")        \
   T(DerivedConstructorReturn,                                                  \
     "Derived constructors may only return object or undefined")                \
   T(DuplicateConstructor, "A class may only have one constructor")             \
   T(DuplicateExport, "Duplicate export of '%'")                                \
   T(DuplicateProto,                                                            \
     "Duplicate __proto__ fields are not allowed in object literals")           \
   T(ForInOfLoopInitializer,                                                    \
     "% loop variable declaration may not have an initializer.")                \
   T(ForInOfLoopMultiBindings,                                                  \
     "Invalid left-hand side in % loop: Must have a single binding.")           \
@@ skipping 54 matching lines @@
   T(StrictDelete, "Delete of an unqualified identifier in strict mode.")       \
   T(StrictEvalArguments, "Unexpected eval or arguments in strict mode")        \
   T(StrictFunction,                                                            \
     "In strict mode code, functions can only be declared at top level or "     \
     "inside a block.")                                                         \
   T(StrictOctalLiteral, "Octal literals are not allowed in strict mode.")      \
   T(StrictWith, "Strict mode code may not include a with statement")           \
   T(TemplateOctalLiteral,                                                      \
     "Octal literals are not allowed in template strings.")                     \
   T(ThisFormalParameter, "'this' is not a valid formal parameter name")        \
+  T(AwaitBindingIdentifier,                                                    \
+    "'await' is not a valid identifier name in an async function")             \
+  T(AwaitExpressionFormalParameter,                                            \
+    "Illegal await-expression in formal parameters of async function")         \
   T(TooManyArguments,                                                          \
     "Too many arguments in function call (only 65535 allowed)")                \
   T(TooManyParameters,                                                         \
     "Too many parameters in function definition (only 65535 allowed)")         \
   T(TooManyVariables, "Too many variables declared (only 4194303 allowed)")    \
   T(TypedArrayTooShort,                                                        \
     "Derived TypedArray constructor created an array which was too small")     \
   T(UnexpectedEOS, "Unexpected end of input")                                  \
   T(UnexpectedFunctionSent,                                                    \
     "function.sent expression is not allowed outside a generator")             \
@@ skipping 80 matching lines @@
   static Handle<String> GetMessage(Isolate* isolate, Handle<Object> data);
   static base::SmartArrayPointer<char> GetLocalizedMessage(Isolate* isolate,
                                                            Handle<Object> data);
 };
 
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_MESSAGES_H_