sink parameter inference for types that have destructors (#13544)

* ensure capitalize doesn't take an inferred sink parameter

* sink parameter inference: first version, for now disabled. Changed that sink parameters can be consumed multiple times in order to adhere to our spec.

* sink inference can now be disabled with .nosinks; sometimes for proc type interop this is required

* fixes yet another critical DFA bug

* better implementation that also understands if expressions etc

* document sink parameter inference and allow for global disabling

tests/destructor/tarc2.nim

@@ -13,9 +13,13 @@ proc create(): T = T(s: @[], data: "abc")
 proc addX(x: T; data: string) =
   x.data = data
 
+{.push sinkInference: off.}
+
 proc addX(x: T; child: T) =
   x.s.add child
 
+{.pop.}
+
 proc main(rootName: string) =
   var root = create()
   root.data = rootName