Reland "Add basic crankshaft support for slow-mode for-in to avoid disabling optimizations"

src/bailout-reason.h

Index: src/bailout-reason.h
diff --git a/src/bailout-reason.h b/src/bailout-reason.h
index e48d5243b9066b26f04dadb6b274c98f15539892..09c889f9dd877dc0505c774f7f8abefda0317c41 100644
--- a/src/bailout-reason.h
+++ b/src/bailout-reason.h
@@ -94,7 +94,6 @@ namespace internal {
   V(kExternalStringExpectedButNotFound,                                        \
     "External string expected, but not found")                                 \
   V(kFailedBailedOutLastTime, "Failed/bailed out last time")                   \
-  V(kForInStatementIsNotFastCase, "ForInStatement is not fast case")           \
   V(kForInStatementOptimizationIsDisabled,                                     \
     "ForInStatement optimization is disabled")                                 \
   V(kForInStatementWithNonLocalEachVariable,                                   \