Put function parameters into their own scope.

runtime/vm/parser.cc

 // Copyright (c) 2011, 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.
 
 #include "vm/parser.h"
 
 #include "vm/bigint_operations.h"
 #include "vm/class_finalizer.h"
 #include "vm/compiler.h"
 #include "vm/compiler_stats.h"
@@ skipping 1816 matching lines @@
     // The instantiator may be required at run time for generic type checks.
     if (IsInstantiatorRequired()) {
       // Make sure that the receiver of the enclosing instance function
       // (or implicit first parameter of an enclosing factory) is marked as
       // captured if type checks are enabled, because they may access the
       // receiver to instantiate types.
       CaptureReceiver();
     }
   }
 
+  OpenBlock();  // Open a nested scope for the outermost function block.
   if (CurrentToken() == Token::kLBRACE) {
     ConsumeToken();
     ParseStatementSequence();
     ExpectToken(Token::kRBRACE);
   } else if (CurrentToken() == Token::kARROW) {
     ConsumeToken();
     const intptr_t expr_pos = token_index_;
     AstNode* expr = ParseExpr(kAllowConst);
     ASSERT(expr != NULL);
     current_block_->statements->Add(new ReturnNode(expr_pos, expr));
   } else if (IsLiteral("native")) {
     ParseNativeFunctionBlock(&params, func);
   } else {
     UnexpectedToken();
   }
-
+  current_block_->statements->Add(CloseBlock());
   SequenceNode* statements = CloseBlock();
   return statements;
 }
 
 
 void Parser::SkipIf(Token::Kind token) {
   if (CurrentToken() == token) {
     ConsumeToken();
   }
 }
@@ skipping 5829 matching lines @@
 }
 
 
 void Parser::SkipNestedExpr() {
   const bool saved_mode = SetAllowFunctionLiterals(true);
   SkipExpr();
   SetAllowFunctionLiterals(saved_mode);
 }
 
 }  // namespace dart