Parse assert statements with Fasta.

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

Index: pkg/front_end/lib/src/fasta/parser/parser.dart
diff --git a/pkg/front_end/lib/src/fasta/parser/parser.dart b/pkg/front_end/lib/src/fasta/parser/parser.dart
index 1f3c4776c62ef57f1d9c28bdd6ca5ad6e53f50d9..34bc5878ba0da1f8b8c345255339f5427b5bca69 100644
--- a/pkg/front_end/lib/src/fasta/parser/parser.dart
+++ b/pkg/front_end/lib/src/fasta/parser/parser.dart
@@ -3507,6 +3507,7 @@ class Parser {
     Token assertKeyword = token;
     Token commaToken = null;
     token = expect('assert', token);
+    Token leftParenthesis = token;
     token = expect('(', token);
     bool old = mayParseFunctionExpressions;
     mayParseFunctionExpressions = true;
@@ -3516,9 +3517,11 @@ class Parser {
       token = token.next;
       token = parseExpression(token);
     }
+    Token rightParenthesis = token;
     token = expect(')', token);
     mayParseFunctionExpressions = old;
-    listener.handleAssertStatement(assertKeyword, commaToken, token);
+    listener.handleAssertStatement(
+        assertKeyword, leftParenthesis, commaToken, rightParenthesis, token);
     return expectSemicolon(token);
   }