[parser] early error when declaration Pattern missing Initializer

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 90 matching lines @@
   T(ConstAssign, "Assignment to constant variable.")                           \
   T(ConstructorNonCallable,                                                    \
     "Class constructors cannot be invoked without 'new'")                      \
   T(ConstructorNotFunction, "Constructor % requires 'new'")                    \
   T(CurrencyCode, "Currency code is required with currency style.")            \
   T(DataViewNotArrayBuffer,                                                    \
     "First argument to DataView constructor must be an ArrayBuffer")           \
   T(DateType, "this is not a Date object.")                                    \
   T(DebuggerFrame, "Debugger: Invalid frame index.")                           \
   T(DebuggerType, "Debugger: Parameters have wrong types.")                    \
+  T(DeclarationMissingInitializer, "Missing initializer in % declaration")     \
   T(DefineDisallowed, "Cannot define property:%, object is not extensible.")   \
   T(DuplicateTemplateProperty, "Object template has duplicate property '%'")   \
   T(ExtendsValueGenerator,                                                     \
     "Class extends value % may not be a generator function")                   \
   T(ExtendsValueNotFunction,                                                   \
     "Class extends value % is not a function or null")                         \
   T(FirstArgumentNotRegExp,                                                    \
     "First argument to % must not be a regular expression")                    \
   T(FlagsGetterNonObject,                                                      \
     "RegExp.prototype.flags getter called on non-object %")                    \
@@ skipping 376 matching lines @@
   static MUST_USE_RESULT MaybeHandle<String> GetStringifiedProperty(
       Isolate* isolate, LookupIterator* property_lookup,
       Handle<String> default_value);
 
   List<Handle<JSObject> > visited_;
 };
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_MESSAGES_H_