[WIP] JSForInLowering and JSForInHasOwnProperty.

src/compiler/simplified-operator.cc

Index: src/compiler/simplified-operator.cc
diff --git a/src/compiler/simplified-operator.cc b/src/compiler/simplified-operator.cc
index f360c4ac0fe419382b7f34e288c1973e8ccc906f..8cfd2818cf9b2c2f03ac8030da1a09425e03acda 100644
--- a/src/compiler/simplified-operator.cc
+++ b/src/compiler/simplified-operator.cc
@@ -657,6 +657,16 @@ struct SimplifiedOperatorGlobalCache final {
   AllocateOperator<NOT_TENURED> kAllocateNotTenuredOperator;
   AllocateOperator<TENURED> kAllocateTenuredOperator;
 
+  struct LoadFieldByIndexOperator final : public Operator {
+    LoadFieldByIndexOperator()
+        : Operator(                         // --
+              IrOpcode::kLoadFieldByIndex,  // opcode
+              Operator::kEliminatable,      // flags,
+              "LoadFieldByIndex",           // name
+              2, 1, 1, 1, 1, 0) {}          // counts;
+  };
+  LoadFieldByIndexOperator kLoadFieldByIndex;
+
   struct EnsureWritableFastElementsOperator final : public Operator {
     EnsureWritableFastElementsOperator()
         : Operator(                                     // --
@@ -721,6 +731,7 @@ PURE_OP_LIST(GET_FROM_CACHE)
 CHECKED_OP_LIST(GET_FROM_CACHE)
 GET_FROM_CACHE(ArrayBufferWasNeutered)
 GET_FROM_CACHE(ArgumentsFrame)
+GET_FROM_CACHE(LoadFieldByIndex)
 GET_FROM_CACHE(NewUnmappedArgumentsElements)
 #undef GET_FROM_CACHE