Introduce basic type feedback for for-in statements to avoid deopts.

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 0b7c7fd451fdc1bdf2dd31ee91b13308f8f8ec9d..86ca138ad25495ea867d0fd43a908edec1a4fb2d 100644
--- a/src/ia32/full-codegen-ia32.cc
+++ b/src/ia32/full-codegen-ia32.cc
@@ -1033,6 +1033,16 @@ void FullCodeGenerator::VisitForInStatement(ForInStatement* stmt) {
   // We got a fixed array in register eax. Iterate through that.
   Label non_proxy;
   __ bind(&fixed_array);
+
+  Handle<JSGlobalPropertyCell> cell =
+      isolate()->factory()->NewJSGlobalPropertyCell(
+          Handle<Object>(
+              Smi::FromInt(TypeFeedbackCells::kForInFastCaseMarker)));
+  RecordTypeFeedbackCell(stmt->PrepareId(), cell);
+  __ LoadHeapObject(ebx, cell);
+  __ mov(FieldOperand(ebx, JSGlobalPropertyCell::kValueOffset),
+         Immediate(Smi::FromInt(TypeFeedbackCells::kForInSlowCaseMarker)));
+
   __ mov(ebx, Immediate(Smi::FromInt(1)));  // Smi indicates slow check
   __ mov(ecx, Operand(esp, 0 * kPointerSize));  // Get enumerated object
   STATIC_ASSERT(FIRST_JS_PROXY_TYPE == FIRST_SPEC_OBJECT_TYPE);