Parse #operator symbol literals with Fasta.

R=paulberry@google.com, ahe@google.com
BUG=

Review-Url: https://codereview.chromium.org/2735623002 .

pkg/analyzer/test/generated/parser_fasta_test.dart

@@ -667,12 +667,6 @@ class ExpressionParserTest_Fasta extends FastaParserTestCase
     super.test_parseSuperConstructorInvocation_unnamed();
   }
 
-  @override
-  @failingTest
-  void test_parseSymbolLiteral_operator() {
-    super.test_parseSymbolLiteral_operator();
-  }
-
   @override
   @failingTest
   void test_parseSymbolLiteral_void() {

pkg/front_end/lib/src/fasta/analyzer/ast_builder.dart

@@ -149,8 +149,14 @@ class AstBuilder extends ScopeListener {
 
   void handleIdentifier(Token token, IdentifierContext context) {
     debugEvent("handleIdentifier");
-    String name = token.value;
-    SimpleIdentifier identifier = ast.simpleIdentifier(toAnalyzerToken(token));
+    analyzer.Token analyzerToken = toAnalyzerToken(token);
+
+    if (context.inSymbol) {
+      push(analyzerToken);
+      return;
+    }
+
+    SimpleIdentifier identifier = ast.simpleIdentifier(analyzerToken);
     if (context.inLibraryOrPartOfDeclaration) {
       if (!context.isContinuation) {
         push([identifier]);
@@ -166,6 +172,7 @@ class AstBuilder extends ScopeListener {
       push(ast.enumConstantDeclaration(comment, metadata, identifier));
     } else {
       if (context.isScopeReference) {
+        String name = token.value;
         Builder builder = scope.lookup(name, token.charOffset, uri);
         if (builder != null) {
           Element element = elementStore[builder];
@@ -263,6 +270,11 @@ class AstBuilder extends ScopeListener {
     push(receiver);
   }
 
+  void handleOperator(Token token) {
+    debugEvent("Operator");
+    push(toAnalyzerToken(token));
+  }
+
   void handleBinaryExpression(Token token) {
     debugEvent("BinaryExpression");
     if (identical(".", token.stringValue) ||
@@ -487,13 +499,9 @@ class AstBuilder extends ScopeListener {
     push(ast.mapLiteralEntry(key, toAnalyzerToken(colon), value));
   }
 
-  void endLiteralSymbol(Token hashToken, int identifierCount) {
+  void endLiteralSymbol(Token hashToken, int tokenCount) {
     debugEvent("LiteralSymbol");
-    List<analyzer.Token> components = new List<analyzer.Token>(identifierCount);
-    for (int i = identifierCount - 1; i >= 0; i--) {
-      SimpleIdentifier identifier = pop();
-      components[i] = identifier.token;
-    }
+    List<analyzer.Token> components = popList(tokenCount);
     push(ast.symbolLiteral(toAnalyzerToken(hashToken), components));
   }
 

pkg/front_end/lib/src/fasta/parser/identifier_context.dart

@@ -200,12 +200,13 @@ class IdentifierContext {
   /// Identifier is the start of a reference occurring in a literal symbol (e.g.
   /// `foo` in `#foo`).
   static const literalSymbol =
-      const IdentifierContext._('literalSymbol', isScopeReference: true);
+      const IdentifierContext._('literalSymbol', inSymbol: true);
 
   /// Identifier is part of a reference occurring in a literal symbol, but it's
   /// not the first identifier of the reference (e.g. `foo` in `#prefix.foo`).
   static const literalSymbolContinuation = const IdentifierContext._(
       'literalSymbolContinuation',
+      inSymbol: true,
       isContinuation: true);
 
   /// Identifier appears in an expression, and it does not immediately follow a
@@ -236,6 +237,9 @@ class IdentifierContext {
   /// declaration.
   final bool inLibraryOrPartOfDeclaration;
 
+  /// Indicates whether the identifier is within a symbol literal.
+  final bool inSymbol;
+
   /// Indicates whether the identifier follows a `.`.
   final bool isContinuation;
 
@@ -244,6 +248,7 @@ class IdentifierContext {
 
   const IdentifierContext._(this._name,
       {this.inLibraryOrPartOfDeclaration: false,
+      this.inSymbol: false,
       this.isContinuation: false,
       this.isScopeReference: false});