Add test case

tests/closure/tcapture.nim

@@ -1,6 +1,9 @@
 discard """
   output: '''
-to be, or not to be'''
+to be, or not to be
+(v: 1)
+(v: 1)
+'''
   joinable: false
 """
 
@@ -9,4 +12,15 @@ import sequtils, sugar
 let m = @[proc (s: string): string = "to " & s, proc (s: string): string = "not to " & s]
 var l = m.mapIt(capture([it], proc (s: string): string = it(s)))
 let r = l.mapIt(it("be"))
-echo r[0] & ", or " & r[1]
+echo r[0] & ", or " & r[1]
+
+type O = object
+  v: int
+var o = O(v: 1)
+var execute: proc()
+capture [o]:
+  execute = proc() =
+    echo o
+execute()
+o.v = -1
+execute()