Disable for-in support in Crankshaft while crashes and regressions are being investigated.

src/hydrogen.cc

Index: src/hydrogen.cc
diff --git a/src/hydrogen.cc b/src/hydrogen.cc
index 6bc8af595d2eb26ac0fb069351560dbf8faad410..4908586f7c757c1654004bd1513930b694908d83 100644
--- a/src/hydrogen.cc
+++ b/src/hydrogen.cc
@@ -3242,6 +3242,10 @@ void HGraphBuilder::VisitForInStatement(ForInStatement* stmt) {
   ASSERT(current_block() != NULL);
   ASSERT(current_block()->HasPredecessor());
 
+  if (!FLAG_optimize_for_in) {
+    return Bailout("ForInStatement optimization is disabled");
+  }
+
   if (!stmt->each()->IsVariableProxy() ||
       !stmt->each()->AsVariableProxy()->var()->IsStackLocal()) {
     return Bailout("ForInStatement with non-local each variable");