Improve handling of parser stack overflows.

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

 // 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.
 
 library fasta.parser.parser;
 
 import '../scanner.dart' show
     ErrorToken;
 
 import '../scanner/recover.dart' show
@@ skipping 1852 matching lines @@
     listener.handleAsyncModifier(async, star);
     return token;
   }
 
   int statementDepth = 0;
   Token parseStatement(Token token) {
     if (statementDepth++ > 500) {
       // This happens for degenerate programs, for example, a lot of nested
       // if-statements. The language test deep_nesting2_negative_test, for
       // example, provokes this.
-      reportRecoverableError(
-          token, ErrorKind.Unspecified, {'text': 'Stack overflow'});
-      return skipToEof(token);
+      return reportUnrecoverableError(token, ErrorKind.StackOverflow);
     }
     Token result = parseStatementX(token);
     statementDepth--;
     return result;
   }
 
   Token parseStatementX(Token token) {
     final value = token.stringValue;
     if (identical(token.kind, IDENTIFIER_TOKEN)) {
       return parseExpressionStatementOrDeclaration(token);
@@ skipping 297 matching lines @@
     }
     return token;
   }
 
   int expressionDepth = 0;
   Token parseExpression(Token token) {
     if (expressionDepth++ > 500) {
       // This happens in degenerate programs, for example, with a lot of nested
       // list literals. This is provoked by, for examaple, the language test
       // deep_nesting1_negative_test.
-      reportRecoverableError(
-          token, ErrorKind.Unspecified, {'text': 'Stack overflow'});
-      return token.next;
+      return reportUnrecoverableError(token, ErrorKind.StackOverflow);
     }
     listener.beginExpression(token);
     Token result = optional('throw', token)
         ? parseThrowExpression(token, true)
         : parsePrecedenceExpression(token, ASSIGNMENT_PRECEDENCE, true);
     expressionDepth--;
     return result;
   }
 
   Token parseExpressionWithoutCascade(Token token) {
@@ skipping 1110 matching lines @@
         break;
     }
     if (isRecoverable) {
       listener.handleRecoverableError(token, kind, arguments);
       return null;
     } else {
       return listener.handleUnrecoverableError(token, kind, arguments);
     }
   }
 }