Move regexp implementation into its own folder.

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

Index: src/regexp/regexp-macro-assembler-irregexp.h
diff --git a/src/regexp-macro-assembler-irregexp.h b/src/regexp/regexp-macro-assembler-irregexp.h
similarity index 96%
rename from src/regexp-macro-assembler-irregexp.h
rename to src/regexp/regexp-macro-assembler-irregexp.h
index 644873339f9c3f90462d9c271cd8d85daa5ddf46..556d78d23d249d9400af0f196b490b8df8239660 100644
--- a/src/regexp-macro-assembler-irregexp.h
+++ b/src/regexp/regexp-macro-assembler-irregexp.h
@@ -2,10 +2,10 @@
 // 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_
+#ifndef V8_REGEXP_REGEXP_MACRO_ASSEMBLER_IRREGEXP_H_
+#define V8_REGEXP_REGEXP_MACRO_ASSEMBLER_IRREGEXP_H_
 
-#include "src/regexp-macro-assembler.h"
+#include "src/regexp/regexp-macro-assembler.h"
 
 namespace v8 {
 namespace internal {
@@ -127,4 +127,4 @@ class RegExpMacroAssemblerIrregexp: public RegExpMacroAssembler {
 
 } }  // namespace v8::internal
 
-#endif  // V8_REGEXP_MACRO_ASSEMBLER_IRREGEXP_H_
+#endif  // V8_REGEXP_REGEXP_MACRO_ASSEMBLER_IRREGEXP_H_