Currently we get a CS2019 warning whenever we use AsyncAttribute
because we ignore the `result` variable on methods whose return
type is != `void` which is the expected behaviour.
This is specially more annoying on third party bindings,
the generated code did not disable this warning so you get
an "unfixable" warning on the generated code and the user
has no way to fix this on their own.
We now disable and restore CS2019 in the generated code as needed.
Nobody likes warnings that are not their fault.
Added unit test.
Build diff:
https://gist.github.com/dalexsoto/6f57d3f84b039b9fda863e2f8cfcf365
Rolf Bjarne Kvinge
Alex Soto