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 5f8d13cf0325f63e1c6b8eea1c9607cfa21f83fd..943e4302dcaf6db22190c0694f6ff69925ff9eb4 100644
--- a/src/crankshaft/hydrogen-instructions.h
+++ b/src/crankshaft/hydrogen-instructions.h
@@ -6189,6 +6189,14 @@ class HObjectAccess final {
     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);