Move regexp implementation into its own folder.

src/regexp/jsregexp.h

 // Copyright 2012 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.
 
-#ifndef V8_JSREGEXP_H_
-#define V8_JSREGEXP_H_
+#ifndef V8_REGEXP_JSREGEXP_H_
+#define V8_REGEXP_JSREGEXP_H_
 
 #include "src/allocation.h"
 #include "src/assembler.h"
 
 namespace v8 {
 namespace internal {
 
 class NodeVisitor;
 class RegExpCompiler;
 class RegExpMacroAssembler;
@@ skipping 1637 matching lines @@
                                    bool is_one_byte);
 
   static bool TooMuchRegExpCode(Handle<String> pattern);
 
   static void DotPrint(const char* label, RegExpNode* node, bool ignore_case);
 };
 
 
 } }  // namespace v8::internal
 
-#endif  // V8_JSREGEXP_H_
+#endif  // V8_REGEXP_JSREGEXP_H_