Move regexp implementation into its own folder.

src/regexp/bytecodes-irregexp.h

Index: src/regexp/bytecodes-irregexp.h
diff --git a/src/bytecodes-irregexp.h b/src/regexp/bytecodes-irregexp.h
similarity index 97%
rename from src/bytecodes-irregexp.h
rename to src/regexp/bytecodes-irregexp.h
index 04b9740acbe55d7187173d23b09660de3f8df2ce..27691422f3700fe4f665d0b06dba541548888025 100644
--- a/src/bytecodes-irregexp.h
+++ b/src/regexp/bytecodes-irregexp.h
@@ -3,8 +3,8 @@
 // found in the LICENSE file.
 
 
-#ifndef V8_BYTECODES_IRREGEXP_H_
-#define V8_BYTECODES_IRREGEXP_H_
+#ifndef V8_REGEXP_BYTECODES_IRREGEXP_H_
+#define V8_REGEXP_BYTECODES_IRREGEXP_H_
 
 namespace v8 {
 namespace internal {
@@ -78,4 +78,4 @@ BYTECODE_ITERATOR(DECLARE_BYTECODE_LENGTH)
 #undef DECLARE_BYTECODE_LENGTH
 } }
 
-#endif  // V8_BYTECODES_IRREGEXP_H_
+#endif  // V8_REGEXP_BYTECODES_IRREGEXP_H_