fix(library/init/breakpoint): missing file

library/init/breakpoint.lean

@@ -0,0 +1,17 @@
+/-
+Copyright (c) 2016 Microsoft Corporation. All rights reserved.
+Released under Apache 2.0 license as described in the file LICENSE.
+Authors: Leonardo de Moura
+-/
+prelude
+import init.meta.attribute init.meta.constructor_tactic
+
+namespace debugger
+
+def attr : user_attribute :=
+{ name  := `breakpoint,
+  descr := "breakpoint for debugger" }
+
+end debugger
+
+run_command attribute.register `debugger.attr