Revert fix for type checking of void type, because some top level tests fail.

runtime/vm/code_generator.cc

 // 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.
 
 #include "vm/code_generator.h"
 
 #include "vm/assembler_macros.h"
 #include "vm/ast.h"
 #include "vm/code_patcher.h"
 #include "vm/compiler.h"
@@ skipping 568 matching lines @@
     Exceptions::CreateAndThrowTypeError(
         location, no_name, no_name, no_name, malformed_error_message);
     UNREACHABLE();
   }
   UpdateTypeTestCache(node_id, instance, type, instantiator,
                       instantiator_type_arguments, result, cache);
   arguments.SetReturn(result);
 }
 
 
-// For error reporting, simplify type name, e.g, all integer types (Smi, Mint,
-// Bigint) are reported as 'int' and all String types are mapped to 'String'.
+// For error reporting simplify type name, e.g, all integer types (Smi, Mint,
+// Bigint) a re reported as 'int'.
 static RawString* GetSimpleTypeName(const Instance& value) {
   if (value.IsInteger()) {
     return String::NewSymbol("int");
-  } else if (value.IsString()) {
-    return String::NewSymbol("String");
   } else {
     return Type::Handle(value.GetType()).Name();
   }
 }
 
 
 // Check that the type of the given instance is a subtype of the given type and
 // can therefore be assigned.
 // Arg0: node-id of the assignment.
 // Arg1: instance being assigned.
@@ skipping 934 matching lines @@
       }
     }
   }
   // The cache is null terminated, therefore the loop above should never
   // terminate by itself.
   UNREACHABLE();
   return Code::null();
 }
 
 }  // namespace dart