Revert of Removed support deprecated (//@|/*@) source(URL|MappingURL)=

src/scanner.cc

 // Copyright 2011 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // Features shared by parsing and pre-parsing scanners.
 
 #include "src/scanner.h"
 
 #include <stdint.h>
 
@@ skipping 338 matching lines @@
   TryToParseSourceURLComment();
   while (c0_ >= 0 && !unicode_cache_->IsLineTerminator(c0_)) {
     Advance();
   }
 
   return Token::WHITESPACE;
 }
 
 
 void Scanner::TryToParseSourceURLComment() {
-  // Magic comments are of the form: //[#]\s<name>=\s*<value>\s*.* and this
+  // Magic comments are of the form: //[#@]\s<name>=\s*<value>\s*.* and this
   // function will just return if it cannot parse a magic comment.
   if (c0_ < 0 || !unicode_cache_->IsWhiteSpace(c0_)) return;
   Advance();
   LiteralBuffer name;
   while (c0_ >= 0 && !unicode_cache_->IsWhiteSpaceOrLineTerminator(c0_) &&
          c0_ != '=') {
     name.AddChar(c0_);
     Advance();
   }
   if (!name.is_one_byte()) return;
@@ skipping 197 matching lines @@
       case '%':
         // % %=
         token = Select('=', Token::ASSIGN_MOD, Token::MOD);
         break;
 
       case '/':
         // /  // /* /=
         Advance();
         if (c0_ == '/') {
           Advance();
-          if (c0_ == '#') {
+          if (c0_ == '@' || c0_ == '#') {
             Advance();
             token = SkipSourceURLComment();
           } else {
             PushBack(c0_);
             token = SkipSingleLineComment();
           }
         } else if (c0_ == '*') {
           token = SkipMultiLineComment();
         } else if (c0_ == '=') {
           token = Select(Token::ASSIGN_DIV);
@@ skipping 1055 matching lines @@
     backing_store_.Add(static_cast<uint8_t>((one_byte_length >> 7) | 0x80u));
   }
   backing_store_.Add(static_cast<uint8_t>(one_byte_length & 0x7f));
 
   backing_store_.AddBlock(bytes);
   return backing_store_.EndSequence().start();
 }
 
 }  // namespace internal
 }  // namespace v8