Move regexp implementation into its own folder.

src/regexp/x87/regexp-macro-assembler-x87.h

Index: src/regexp/x87/regexp-macro-assembler-x87.h
diff --git a/src/x87/regexp-macro-assembler-x87.h b/src/regexp/x87/regexp-macro-assembler-x87.h
similarity index 97%
rename from src/x87/regexp-macro-assembler-x87.h
rename to src/regexp/x87/regexp-macro-assembler-x87.h
index 0af947995d86173749fde1012ee4872ef4e822b2..f636ca08ce5e1c08eb5c0fae7a900eead9b2f472 100644
--- a/src/x87/regexp-macro-assembler-x87.h
+++ b/src/regexp/x87/regexp-macro-assembler-x87.h
@@ -2,10 +2,11 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#ifndef V8_X87_REGEXP_MACRO_ASSEMBLER_X87_H_
-#define V8_X87_REGEXP_MACRO_ASSEMBLER_X87_H_
+#ifndef V8_REGEXP_X87_REGEXP_MACRO_ASSEMBLER_X87_H_
+#define V8_REGEXP_X87_REGEXP_MACRO_ASSEMBLER_X87_H_
 
 #include "src/macro-assembler.h"
+#include "src/regexp/regexp-macro-assembler.h"
 #include "src/x87/assembler-x87.h"
 
 namespace v8 {
@@ -197,4 +198,4 @@ class RegExpMacroAssemblerX87: public NativeRegExpMacroAssembler {
 
 }}  // namespace v8::internal
 
-#endif  // V8_X87_REGEXP_MACRO_ASSEMBLER_X87_H_
+#endif  // V8_REGEXP_X87_REGEXP_MACRO_ASSEMBLER_X87_H_