Although I don't plan to bring over new assertions wholesale
into the current qualification branch, it's entirely possible
that various minor changes in main will use the new assertions;
having this basic support in the release branch will simplify that.
(This is why I'm adding the includes as a separate pass from
rewriting the individual assertions)
Importantly this also lets us use the analysis framework to validate that we do
properly invalidate DeadEndBlocks, preventing bugs.
I did not thread this all over the compiler. Instead I just used it for now in
SemanticARCOpts just to add some coverage without threading it into too many
places.
