Make compilation VM tags more fine grained

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 842 matching lines @@
           ErrorMsg(msg);
           ReadChar();
         }
     }
   } while (current_token_.kind == Token::kWHITESP);
 }
 
 
 void Scanner::ScanAll(GrowableTokenStream* token_stream) {
   Reset();
+  VMTagScope(Isolate::Current(), VMTag::kCompileScannerTagId);
   do {
     Scan();
 
     bool inserted_new_lines = false;
     for (intptr_t diff = current_token_.position.line - prev_token_line_;
          diff > 0;
          diff--) {
       newline_token_.position.line = current_token_.position.line - diff;
       token_stream->Add(newline_token_);
       inserted_new_lines = true;
@@ skipping 67 matching lines @@
   for (int i = 0; i < Token::numKeywords; i++) {
     Token::Kind token = static_cast<Token::Kind>(Token::kFirstKeyword + i);
     keywords_[i].kind = token;
     keywords_[i].keyword_chars = Token::Str(token);
     keywords_[i].keyword_len = strlen(Token::Str(token));
     keywords_[i].keyword_symbol = &Symbols::Keyword(token);
   }
 }
 
 }  // namespace dart