Revert 20348 - "Fix LoadFieldByIndex to take mutable heap-numbers into account."

src/runtime.cc

Index: src/runtime.cc
diff --git a/src/runtime.cc b/src/runtime.cc
index 78f379513242f5787112356c04b86205424ec4eb..849de3cb1e204befd6ec0fb807cdb8dd7c07be1d 100644
--- a/src/runtime.cc
+++ b/src/runtime.cc
@@ -14508,19 +14508,6 @@ RUNTIME_FUNCTION(MaybeObject*, Runtime_NotifyContextDisposed) {
 }
 
 
-RUNTIME_FUNCTION(MaybeObject*, Runtime_LoadMutableDouble) {
-  HandleScope scope(isolate);
-  ASSERT(args.length() == 2);
-  CONVERT_ARG_HANDLE_CHECKED(JSObject, object, 0);
-  CONVERT_ARG_HANDLE_CHECKED(Smi, index, 1);
-  int idx = index->value() >> 1;
-  if (idx < 0) {
-    idx = -idx + object->map()->inobject_properties() - 1;
-  }
-  return *JSObject::FastPropertyAt(object, Representation::Double(), idx);
-}
-
-
 RUNTIME_FUNCTION(MaybeObject*, Runtime_TryMigrateInstance) {
   HandleScope scope(isolate);
   ASSERT(args.length() == 1);