Test for var declarations in eval which conflict with let

src/contexts.h

Index: src/contexts.h
diff --git a/src/contexts.h b/src/contexts.h
index f6d196ba9dbfc696e4b8ac82ce00a2dd0dd7b5fe..4cfae048b4ea98802a4973ca8f4d7434e26feb69 100644
--- a/src/contexts.h
+++ b/src/contexts.h
@@ -13,11 +13,15 @@ namespace internal {
 
 
 enum ContextLookupFlags {
-  FOLLOW_CONTEXT_CHAIN = 1,
-  FOLLOW_PROTOTYPE_CHAIN = 2,
+  FOLLOW_CONTEXT_CHAIN = 1 << 0,
+  FOLLOW_PROTOTYPE_CHAIN = 1 << 1,
+  STOP_AT_DECLARATION_SCOPE = 1 << 2,
+  SKIP_WITH_CONTEXT = 1 << 3,
 
   DONT_FOLLOW_CHAINS = 0,
-  FOLLOW_CHAINS = FOLLOW_CONTEXT_CHAIN | FOLLOW_PROTOTYPE_CHAIN
+  FOLLOW_CHAINS = FOLLOW_CONTEXT_CHAIN | FOLLOW_PROTOTYPE_CHAIN,
+  LEXICAL_TEST =
+      FOLLOW_CONTEXT_CHAIN | STOP_AT_DECLARATION_SCOPE | SKIP_WITH_CONTEXT,
 };