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

changelog.md

@@ -127,7 +127,6 @@ echo f
 - `=sink` type bound operator is now optional. Compiler can now use combination
   of `=destroy` and `copyMem` to move objects efficiently.
 
-
 ## Language changes
 
 - Unsigned integer operators have been fixed to allow promotion of the first operand.
@@ -150,6 +149,9 @@ echo f
 - The Nim compiler now supports a new pragma called ``.localPassc`` to
   pass specific compiler options to the C(++) backend for the C(++) file
   that was produced from the current Nim module.
+- The compiler now inferes "sink parameters". To disable this for a specific routine,
+  annotate it with `.nosinks`. To disable it for a section of code, use
+  `{.push sinkInference: off.}`...`{.pop.}`.
 
 
 ## Bugfixes