Use identical in token operators.

pkg/front_end/lib/src/fasta/scanner/precedence.dart

Index: pkg/front_end/lib/src/fasta/scanner/precedence.dart
diff --git a/pkg/front_end/lib/src/fasta/scanner/precedence.dart b/pkg/front_end/lib/src/fasta/scanner/precedence.dart
index d1a222b9481f72edf645a064dfbd0d54a1fad43e..bfc5c881cba204261b82bfdd17b111cc2626757d 100644
--- a/pkg/front_end/lib/src/fasta/scanner/precedence.dart
+++ b/pkg/front_end/lib/src/fasta/scanner/precedence.dart
@@ -14,6 +14,82 @@ class PrecedenceInfo {
   const PrecedenceInfo(this.value, this.precedence, this.kind);
 
   toString() => 'PrecedenceInfo($value, $precedence, $kind)';
+
+  static const List<PrecedenceInfo> all = const <PrecedenceInfo>[
+      BACKPING_INFO,
+      BACKSLASH_INFO,
+      PERIOD_PERIOD_PERIOD_INFO,
+      PERIOD_PERIOD_INFO,
+      BANG_INFO,
+      COLON_INFO,
+      INDEX_INFO,
+      MINUS_MINUS_INFO,
+      PLUS_PLUS_INFO,
+      TILDE_INFO,
+      FUNCTION_INFO,
+      HASH_INFO,
+      INDEX_EQ_INFO,
+      SEMICOLON_INFO,
+      COMMA_INFO,
+      AT_INFO,
+      AMPERSAND_EQ_INFO,
+      BAR_EQ_INFO,
+      CARET_EQ_INFO,
+      EQ_INFO,
+      GT_GT_EQ_INFO,
+      LT_LT_EQ_INFO,
+      MINUS_EQ_INFO,
+      PERCENT_EQ_INFO,
+      PLUS_EQ_INFO,
+      SLASH_EQ_INFO,
+      STAR_EQ_INFO,
+      TILDE_SLASH_EQ_INFO,
+      QUESTION_QUESTION_EQ_INFO,
+      QUESTION_INFO,
+      QUESTION_QUESTION_INFO,
+      BAR_BAR_INFO,
+      AMPERSAND_AMPERSAND_INFO,
+      BAR_INFO,
+      CARET_INFO,
+      AMPERSAND_INFO,
+      BANG_EQ_EQ_INFO,
+      BANG_EQ_INFO,
+      EQ_EQ_EQ_INFO,
+      EQ_EQ_INFO,
+      GT_EQ_INFO,
+      GT_INFO,
+      IS_INFO,
+      AS_INFO,
+      LT_EQ_INFO,
+      LT_INFO,
+      GT_GT_INFO,
+      LT_LT_INFO,
+      MINUS_INFO,
+      PLUS_INFO,
+      PERCENT_INFO,
+      SLASH_INFO,
+      STAR_INFO,
+      TILDE_SLASH_INFO,
+      PERIOD_INFO,
+      QUESTION_PERIOD_INFO,
+      KEYWORD_INFO,
+      EOF_INFO,
+      IDENTIFIER_INFO,
+      BAD_INPUT_INFO,
+      OPEN_PAREN_INFO,
+      CLOSE_PAREN_INFO,
+      OPEN_CURLY_BRACKET_INFO,
+      CLOSE_CURLY_BRACKET_INFO,
+      INT_INFO,
+      STRING_INFO,
+      OPEN_SQUARE_BRACKET_INFO,
+      CLOSE_SQUARE_BRACKET_INFO,
+      DOUBLE_INFO,
+      STRING_INTERPOLATION_INFO,
+      STRING_INTERPOLATION_IDENTIFIER_INFO,
+      HEXADECIMAL_INFO,
+      COMMENT_INFO,
+    ];
 }
 
 // TODO(ahe): The following are not tokens in Dart.