[Parse] Add a test for the change.

Author: Davide Italiano

test/Parse/closure-debugger.swift

@@ -0,0 +1,6 @@
+// RUN: not %target-swift-frontend %s -typecheck -debugger-support 2>&1 | %FileCheck %s --check-prefix=DEBUG
+// RUN: not %target-swift-frontend %s -typecheck 2>&1 | %FileCheck %s --check-prefix=NODEBUG
+
+// DEBUG: error: use of unresolved identifier '$0'
+// NODEBUG: error: anonymous closure argument not contained in a closure
+$0