Add --trace_type_check_elimination flag for debugging purposes.

runtime/vm/parser.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/parser.h"
 
 #include "vm/bigint_operations.h"
 #include "vm/class_finalizer.h"
 #include "vm/compiler.h"
 #include "vm/compiler_stats.h"
@@ skipping 5747 matching lines @@
     // Script is unknown.
     // Append the formatted error or warning message.
     msg_len += OS::VSNPrint(message_buffer + msg_len,
                             message_buffer_size - msg_len,
                             format,
                             args);
   }
 }
 
 
+void Parser::PrintMessage(const Script& script,
+                          intptr_t token_pos,
+                          const char* message_header,
+                          const char* format, ...) {
+  va_list args;
+  va_start(args, format);
+  const intptr_t kMessageBufferSize = 512;
+  char message_buffer[kMessageBufferSize];
+  FormatMessage(script, token_pos, message_header,
+                message_buffer, kMessageBufferSize,
+                format, args);
+  va_end(args);
+  OS::Print("%s", message_buffer);
+}
+
+
 void Parser::ErrorMsg(intptr_t token_pos, const char* format, ...) {
   va_list args;
   va_start(args, format);
   const Error& error = Error::Handle(
       FormatError(script_, token_pos, "Error", format, args));
   va_end(args);
   Isolate::Current()->long_jump_base()->Jump(1, error);
   UNREACHABLE();
 }
 
@@ skipping 2856 matching lines @@
 void Parser::SkipQualIdent() {
   ASSERT(IsIdentifier());
   ConsumeToken();
   if (CurrentToken() == Token::kPERIOD) {
     ConsumeToken();  // Consume the kPERIOD token.
     ExpectIdentifier("identifier expected after '.'");
   }
 }
 
 }  // namespace dart