[cxx-interop] Inject escapability for the C++ standard library
We only add conditional annotations because those do not break backward
compatibility (we might import span and similar view types as
non-escapable in the future). We inject these annotations in the
importer to make sure we have consistent behavior acress the different
standard library implementations. Once we can ship APINotes for the STL
and we have conditional escapability support in APINotes we can migrate
to that solution. But it is not possible as of today and Clang already
has precedent of injecting information for the STL with lifetimebound.
rdar://139065558