[turbofan] Fix --turbo-osr for OSRing into inner loop inside for-in.

src/compiler/ast-graph-builder.cc

Index: src/compiler/ast-graph-builder.cc
diff --git a/src/compiler/ast-graph-builder.cc b/src/compiler/ast-graph-builder.cc
index 96809fc2dff053b92817c2ffd0bdf7ad66a819d5..5c874bc8b52cda3ada0456241050a20aadc50b75 100644
--- a/src/compiler/ast-graph-builder.cc
+++ b/src/compiler/ast-graph-builder.cc
@@ -1194,7 +1194,9 @@ void AstGraphBuilder::VisitForInBody(ForInStatement* stmt) {
   // Bind value and do loop body.
   VisitForInAssignment(stmt->each(), value, stmt->AssignmentId());
   VisitIterationBody(stmt, &for_loop);
+  index = environment()->Peek(0);
   for_loop.EndBody();
+
   // Inc counter and continue.
   Node* index_inc =
       NewNode(javascript()->Add(), index, jsgraph()->OneConstant());