[wasm][asm.js] Adding custom asm.js lexer.

src/parsing/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/parsing/scanner.h"
 
 #include <stdint.h>
 
@@ skipping 1147 matching lines @@
   return ScanTemplateSpan();
 }
 
 
 Token::Value Scanner::ScanTemplateContinuation() {
   DCHECK_EQ(next_.token, Token::RBRACE);
   next_.location.beg_pos = source_pos() - 1;  // We already consumed }
   return ScanTemplateSpan();
 }
 
+Handle<String> Scanner::SourceUrl(Isolate* isolate) const {
+  Handle<String> tmp;
+  if (source_url_.length() > 0) tmp = source_url_.Internalize(isolate);
+  return tmp;
+}
+
+Handle<String> Scanner::SourceMappingUrl(Isolate* isolate) const {
+  Handle<String> tmp;
+  if (source_mapping_url_.length() > 0)
+    tmp = source_mapping_url_.Internalize(isolate);
+  return tmp;
+}
 
 void Scanner::ScanDecimalDigits() {
   while (IsDecimalDigit(c0_))
     AddLiteralCharAdvance();
 }
 
 
 Token::Value Scanner::ScanNumber(bool seen_period) {
   DCHECK(IsDecimalDigit(c0_));  // the first digit of the number or the fraction
 
@@ skipping 566 matching lines @@
   // 2, reset the source to the desired position,
   source_->Seek(position);
   // 3, re-scan, by scanning the look-ahead char + 1 token (next_).
   c0_ = source_->Advance();
   Next();
   DCHECK_EQ(next_.location.beg_pos, static_cast<int>(position));
 }
 
 }  // namespace internal
 }  // namespace v8