Remove grab-bag includes of v8.h from regexp engine.

src/regexp/regexp-macro-assembler.cc

Index: src/regexp/regexp-macro-assembler.cc
diff --git a/src/regexp/regexp-macro-assembler.cc b/src/regexp/regexp-macro-assembler.cc
index 5bc1d94017c1e5942684684c7349897c4c79bc42..20105c0b30656cc853f5ba4a2261d114a852a988 100644
--- a/src/regexp/regexp-macro-assembler.cc
+++ b/src/regexp/regexp-macro-assembler.cc
@@ -2,11 +2,10 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#include "src/v8.h"
+#include "src/regexp/regexp-macro-assembler.h"
 
 #include "src/assembler.h"
 #include "src/ast.h"
-#include "src/regexp/regexp-macro-assembler.h"
 #include "src/regexp/regexp-stack.h"
 #include "src/simulator.h"