Revert of Use in-object fields instead of private symbols for regexp slots.

src/crankshaft/hydrogen-instructions.h

Index: src/crankshaft/hydrogen-instructions.h
diff --git a/src/crankshaft/hydrogen-instructions.h b/src/crankshaft/hydrogen-instructions.h
index 98d88fb911ecdcaff4da0cc17f236fe8efcee245..050c771d2c07feccd217c0ed15277d1b57c8ea44 100644
--- a/src/crankshaft/hydrogen-instructions.h
+++ b/src/crankshaft/hydrogen-instructions.h
@@ -6195,14 +6195,6 @@
     return HObjectAccess(kInobject, JSGlobalObject::kNativeContextOffset);
   }
 
-  static HObjectAccess ForJSRegExpFlags() {
-    return HObjectAccess(kInobject, JSRegExp::kFlagsOffset);
-  }
-
-  static HObjectAccess ForJSRegExpSource() {
-    return HObjectAccess(kInobject, JSRegExp::kSourceOffset);
-  }
-
   static HObjectAccess ForJSCollectionTable() {
     return HObjectAccess::ForObservableJSObjectOffset(
         JSCollection::kTableOffset);