Continued fix for 351257. Reusing the feedback vector is too complex.

src/ia32/full-codegen-ia32.cc

Index: src/ia32/full-codegen-ia32.cc
diff --git a/src/ia32/full-codegen-ia32.cc b/src/ia32/full-codegen-ia32.cc
index 096e2edb119000da4ae6e1013aefaa8e9f219c0d..06da7ba0e7d521844523e756106ee2e090756ac6 100644
--- a/src/ia32/full-codegen-ia32.cc
+++ b/src/ia32/full-codegen-ia32.cc
@@ -119,8 +119,6 @@ void FullCodeGenerator::Generate() {
   handler_table_ =
       isolate()->factory()->NewFixedArray(function()->handler_count(), TENURED);
 
-  InitializeFeedbackVector();
-
   profiling_counter_ = isolate()->factory()->NewCell(
       Handle<Smi>(Smi::FromInt(FLAG_interrupt_budget), isolate()));
   SetFunctionPosition(function());
@@ -1104,15 +1102,10 @@ void FullCodeGenerator::VisitForInStatement(ForInStatement* stmt) {
   Label non_proxy;
   __ bind(&fixed_array);
 
-  Handle<Object> feedback = Handle<Object>(
-      Smi::FromInt(TypeFeedbackInfo::kForInFastCaseMarker),
-      isolate());
-  StoreFeedbackVectorSlot(slot, feedback);
-
   // No need for a write barrier, we are storing a Smi in the feedback vector.
   __ LoadHeapObject(ebx, FeedbackVector());
   __ mov(FieldOperand(ebx, FixedArray::OffsetOfElementAt(slot)),
-         Immediate(Smi::FromInt(TypeFeedbackInfo::kForInSlowCaseMarker)));
+         Immediate(TypeFeedbackInfo::MegamorphicSentinel(isolate())));
 
   __ mov(ebx, Immediate(Smi::FromInt(1)));  // Smi indicates slow check
   __ mov(ecx, Operand(esp, 0 * kPointerSize));  // Get enumerated object
@@ -2665,9 +2658,6 @@ void FullCodeGenerator::EmitCallWithStub(Call* expr) {
   // Record source position for debugger.
   SetSourcePosition(expr->position());
 
-  Handle<Object> uninitialized =
-      TypeFeedbackInfo::UninitializedSentinel(isolate());
-  StoreFeedbackVectorSlot(expr->CallFeedbackSlot(), uninitialized);
   __ LoadHeapObject(ebx, FeedbackVector());
   __ mov(edx, Immediate(Smi::FromInt(expr->CallFeedbackSlot())));
 
@@ -2845,9 +2835,6 @@ void FullCodeGenerator::VisitCallNew(CallNew* expr) {
   __ mov(edi, Operand(esp, arg_count * kPointerSize));
 
   // Record call targets in unoptimized code.
-  Handle<Object> uninitialized =
-      TypeFeedbackInfo::UninitializedSentinel(isolate());
-  StoreFeedbackVectorSlot(expr->CallNewFeedbackSlot(), uninitialized);
   __ LoadHeapObject(ebx, FeedbackVector());
   __ mov(edx, Immediate(Smi::FromInt(expr->CallNewFeedbackSlot())));