Remove several grab-bag includes from the v8.h header.

src/regexp-macro-assembler-irregexp.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_REGEXP_MACRO_ASSEMBLER_IRREGEXP_H_
 #define V8_REGEXP_MACRO_ASSEMBLER_IRREGEXP_H_
 
 #include "src/regexp-macro-assembler.h"
 
 namespace v8 {
 namespace internal {
 
 #ifdef V8_INTERPRETED_REGEXP
 
+// A light-weight assembler for the Irregexp byte code.
 class RegExpMacroAssemblerIrregexp: public RegExpMacroAssembler {
  public:
   // Create an assembler. Instructions and relocation information are emitted
   // into a buffer, with the instructions starting from the beginning and the
   // relocation information starting from the end of the buffer. See CodeDesc
   // for a detailed comment on the layout (globals.h).
   //
   // If the provided buffer is NULL, the assembler allocates and grows its own
   // buffer, and buffer_size determines the initial buffer size. The buffer is
   // owned by the assembler and deallocated upon destruction of the assembler.
@@ skipping 95 matching lines @@
   static const int kInvalidPC = -1;
 
   DISALLOW_IMPLICIT_CONSTRUCTORS(RegExpMacroAssemblerIrregexp);
 };
 
 #endif  // V8_INTERPRETED_REGEXP
 
 } }  // namespace v8::internal
 
 #endif  // V8_REGEXP_MACRO_ASSEMBLER_IRREGEXP_H_