Add --trace_type_check_elimination flag for debugging purposes.

runtime/vm/parser.h

 // 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.
 
 #ifndef VM_PARSER_H_
 #define VM_PARSER_H_
 
 #include "include/dart_api.h"
 
 #include "vm/ast.h"
@@ skipping 127 matching lines @@
   Parser(const Script& script, const Library& library);
   Parser(const Script& script, const Function& function, intptr_t token_pos);
 
   // Parse the top level of a whole script file and register declared classes
   // and interfaces in the given library.
   static void ParseCompilationUnit(const Library& library,
                                    const Script& script);
 
   static void ParseFunction(ParsedFunction* parsed_function);
 
+  // Format and print a message with source location.
+  // A null script means no source and a negative token_pos means no position.
+  static void PrintMessage(const Script& script,
+                           intptr_t token_pos,
+                           const char* message_header,
+                           const char* format, ...);
+
   // Build an error object containing a formatted error or warning message.
   // A null script means no source and a negative token_pos means no position.
   static RawError* FormatError(const Script& script,
                                intptr_t token_pos,
                                const char* message_header,
                                const char* format,
                                va_list args);
 
   // Same as FormatError, but appends the new error to the 'prev_error'.
   static RawError* FormatErrorWithAppend(const Error& prev_error,
@@ skipping 411 matching lines @@
 
   // Allocate temporary only once per function.
   LocalVariable* expression_temp_;
 
   DISALLOW_COPY_AND_ASSIGN(Parser);
 };
 
 }  // namespace dart
 
 #endif  // VM_PARSER_H_