Test for var declarations in eval which conflict with let

src/contexts.cc

Index: src/contexts.cc
diff --git a/src/contexts.cc b/src/contexts.cc
index a008d49ac37ebfdf9e47cdcb995eac2fba591918..a18f181bef8ccb3e0ca80d43dc5a1f3107105d73 100644
--- a/src/contexts.cc
+++ b/src/contexts.cc
@@ -264,7 +264,8 @@ Handle<Object> Context::Lookup(Handle<String> name,
     }
 
     // 1. Check global objects, subjects of with, and extension objects.
-    if ((context->IsNativeContext() || context->IsWithContext() ||
+    if ((context->IsNativeContext() ||
+         (context->IsWithContext() && ((flags & SKIP_WITH_CONTEXT) == 0)) ||
          context->IsFunctionContext() || context->IsBlockContext()) &&
         context->extension_receiver() != nullptr) {
       Handle<JSReceiver> object(context->extension_receiver());
@@ -384,7 +385,9 @@ Handle<Object> Context::Lookup(Handle<String> name,
     }
 
     // 3. Prepare to continue with the previous (next outermost) context.
-    if (context->IsNativeContext()) {
+    if (context->IsNativeContext() ||
+        ((flags & STOP_AT_DECLARATION_SCOPE) != 0 &&
+         context->is_declaration_context())) {
       follow_context_chain = false;
     } else {
       context = Handle<Context>(context->previous(), isolate);