Filter out synthetic variables from with scopes

src/contexts.cc

Index: src/contexts.cc
diff --git a/src/contexts.cc b/src/contexts.cc
index 3447b42f47dc32d3f37055fc36d9fa30f365ab43..4fb3c833b773195f706c52bcec56cddd8d932ebe 100644
--- a/src/contexts.cc
+++ b/src/contexts.cc
@@ -261,8 +261,14 @@ Handle<Object> Context::Lookup(Handle<String> name, ContextLookupFlags flags,
           object->IsJSContextExtensionObject()) {
         maybe = JSReceiver::GetOwnPropertyAttributes(object, name);
       } else if (context->IsWithContext()) {
-        // A with context will never bind "this".
-        if (name->Equals(*isolate->factory()->this_string())) {
+        // A with context will never bind "this", but debug-eval may look into
+        // a with context when resolving "this". Other synthetic variables such
+        // as new.target may be resolved as DYNAMIC_LOCAL due to bug v8:5405 ,
+        // skipping them here serves as a workaround until a more thorough
+        // fix can be applied.
+        // TODO(v8:5405): Replace this check with a DCHECK when resolution of
+        // of synthetic variables does not go through this code path.
+        if (ScopeInfo::VariableIsSynthetic(*name)) {
           maybe = Just(ABSENT);
         } else {
           LookupIterator it(object, name, object);