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

src/full-codegen/arm/full-codegen-arm.cc

Index: src/full-codegen/arm/full-codegen-arm.cc
diff --git a/src/full-codegen/arm/full-codegen-arm.cc b/src/full-codegen/arm/full-codegen-arm.cc
index ab0717460d6be6c6df3c57d9a31a39929368999c..2c1ab705a51d3fdd16a820320d146f4ca64f11e8 100644
--- a/src/full-codegen/arm/full-codegen-arm.cc
+++ b/src/full-codegen/arm/full-codegen-arm.cc
@@ -1076,10 +1076,6 @@ void FullCodeGenerator::VisitForInStatement(ForInStatement* stmt) {
   // We got a fixed array in register r0. Iterate through that.
   __ bind(&fixed_array);
 
-  int const vector_index = SmiFromSlot(slot)->value();
-  __ EmitLoadTypeFeedbackVector(r1);
-  __ mov(r2, Operand(TypeFeedbackVector::MegamorphicSentinel(isolate())));
-  __ str(r2, FieldMemOperand(r1, FixedArray::OffsetOfElementAt(vector_index)));
   __ mov(r1, Operand(Smi::FromInt(1)));  // Smi(1) indicates slow check
   __ Push(r1, r0);  // Smi and array
   __ ldr(r1, FieldMemOperand(r0, FixedArray::kLengthOffset));
@@ -1114,12 +1110,8 @@ void FullCodeGenerator::VisitForInStatement(ForInStatement* stmt) {
   __ cmp(r4, Operand(r2));
   __ b(eq, &update_each);
 
-  // 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(r0);
   __ mov(r2, Operand(TypeFeedbackVector::MegamorphicSentinel(isolate())));
   __ str(r2, FieldMemOperand(r0, FixedArray::OffsetOfElementAt(vector_index)));