Replace intptr_t with TokenDescriptor

runtime/vm/scanner.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/scanner.h"
 
 #include "platform/assert.h"
 #include "vm/dart.h"
 #include "vm/flags.h"
 #include "vm/object.h"
@@ skipping 891 matching lines @@
       // Script::GenerateLineNumberArray to stay in sync.
       empty_string_token_.position.line = current_token_.position.line;
       token_stream->Add(empty_string_token_);
     }
     token_stream->Add(current_token_);
     prev_token_line_ = current_token_.position.line;
   } while (current_token_.kind != Token::kEOS);
 }
 
 
-void Scanner::ScanTo(intptr_t token_index) {
-  int index = 0;
+void Scanner::ScanTo(TokenPosition token_index) {
+  TokenPosition index = TokenPosition::kMinSource;
   Reset();
   do {
     Scan();
 
     bool inserted_new_lines = false;
     for (intptr_t diff = current_token_.position.line - prev_token_line_;
          diff > 0;
          diff--) {
-      index++;  // Advance the index to account for tokens added in ScanAll.
+      // Advance the index to account for tokens added in ScanAll.
+      index.Next();
       inserted_new_lines = true;
     }
 
     if (inserted_new_lines &&
         ((current_token_.kind == Token::kINTERPOL_VAR) ||
          (current_token_.kind == Token::kINTERPOL_START))) {
-          index++;  // Advance the index to account for tokens added in ScanAll.
+          // Advance the index to account for tokens added in ScanAll.
+          index.Next();
     }
-    index++;
+    index.Next();
     prev_token_line_ = current_token_.position.line;
   } while ((token_index >= index) && (current_token_.kind != Token::kEOS));
 }
 
 
 const Scanner::GrowableTokenStream& Scanner::GetStream() {
   GrowableTokenStream* ts = new(Z) GrowableTokenStream(128);
   ScanAll(ts);
   if (FLAG_print_tokens) {
     Scanner::PrintTokens(*ts);
@@ skipping 29 matching lines @@
     keywords_[i].keyword_symbol = &Symbols::Keyword(token);
 
     int ch = keywords_[i].keyword_chars[0] - 'a';
     if (keywords_char_offset_[ch] == Token::kNumKeywords) {
       keywords_char_offset_[ch] = i;
     }
   }
 }
 
 }  // namespace dart