Support covariant keyword in the VM parser

runtime/vm/token.h

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #ifndef RUNTIME_VM_TOKEN_H_
 #define RUNTIME_VM_TOKEN_H_
 
 #include "platform/assert.h"
 #include "vm/allocation.h"
 
@@ skipping 137 matching lines @@
 #define DART_KEYWORD_LIST(KW)                                                  \
   KW(kABSTRACT, "abstract", 0, kPseudoKeyword) /* == kFirstKeyword */          \
   KW(kAS, "as", 11, kPseudoKeyword)                                            \
   KW(kASSERT, "assert", 11, kKeyword)                                          \
   KW(kBREAK, "break", 0, kKeyword)                                             \
   KW(kCASE, "case", 0, kKeyword)                                               \
   KW(kCATCH, "catch", 0, kKeyword)                                             \
   KW(kCLASS, "class", 0, kKeyword)                                             \
   KW(kCONST, "const", 0, kKeyword)                                             \
   KW(kCONTINUE, "continue", 0, kKeyword)                                       \
+  KW(kCOVARIANT, "covariant", 0, kPseudoKeyword)                               \
   KW(kDEFAULT, "default", 0, kKeyword)                                         \
   KW(kDO, "do", 0, kKeyword)                                                   \
   KW(kELSE, "else", 0, kKeyword)                                               \
   KW(kENUM, "enum", 0, kKeyword)                                               \
   KW(kEXPORT, "export", 0, kPseudoKeyword)                                     \
   KW(kEXTENDS, "extends", 0, kKeyword)                                         \
   KW(kEXTERNAL, "external", 0, kPseudoKeyword)                                 \
   KW(kFACTORY, "factory", 0, kPseudoKeyword)                                   \
   KW(kFALSE, "false", 0, kKeyword)                                             \
   KW(kFINAL, "final", 0, kKeyword)                                             \
@@ skipping 156 matching lines @@
  private:
   static const char* name_[];
   static const char* tok_str_[];
   static const uint8_t precedence_[];
   static const Attribute attributes_[];
 };
 
 }  // namespace dart
 
 #endif  // RUNTIME_VM_TOKEN_H_