[for-in] Record slow path feedback only when we hit %ForInFilter.

src/full-codegen/mips/full-codegen-mips.cc

Index: src/full-codegen/mips/full-codegen-mips.cc
diff --git a/src/full-codegen/mips/full-codegen-mips.cc b/src/full-codegen/mips/full-codegen-mips.cc
index be117a733d66f7429ef68cae03dc5d6cc34e1a71..2e0aeb04647782ceae3ccd3f34dca2cfbd687fda 100644
--- a/src/full-codegen/mips/full-codegen-mips.cc
+++ b/src/full-codegen/mips/full-codegen-mips.cc
@@ -1072,11 +1072,6 @@ void FullCodeGenerator::VisitForInStatement(ForInStatement* stmt) {
   // We got a fixed array in register v0. Iterate through that.
   __ bind(&fixed_array);
 
-  int const vector_index = SmiFromSlot(slot)->value();
-  __ EmitLoadTypeFeedbackVector(a1);
-  __ li(a2, Operand(TypeFeedbackVector::MegamorphicSentinel(isolate())));
-  __ sw(a2, FieldMemOperand(a1, FixedArray::OffsetOfElementAt(vector_index)));
-
   __ li(a1, Operand(Smi::FromInt(1)));  // Smi(1) indicates slow check
   __ Push(a1, v0);  // Smi and array
   __ lw(a1, FieldMemOperand(v0, FixedArray::kLengthOffset));
@@ -1111,12 +1106,8 @@ void FullCodeGenerator::VisitForInStatement(ForInStatement* stmt) {
   __ lw(t0, FieldMemOperand(a1, HeapObject::kMapOffset));
   __ Branch(&update_each, eq, t0, Operand(a2));
 
-  // We might get here from TurboFan or Crankshaft when something in the
-  // for-in loop body deopts and only now notice in fullcodegen, that we
-  // can now longer use the enum cache, i.e. left fast mode. So better record
-  // this information here, in case we later OSR back into this loop or
-  // reoptimize the whole function w/o rerunning the loop with the slow
-  // mode object in fullcodegen (which would result in a deopt loop).
+  // We need to filter the key, record slow-path here.
+  int const vector_index = SmiFromSlot(slot)->value();
   __ EmitLoadTypeFeedbackVector(a0);
   __ li(a2, Operand(TypeFeedbackVector::MegamorphicSentinel(isolate())));
   __ sw(a2, FieldMemOperand(a0, FixedArray::OffsetOfElementAt(vector_index)));