There is already precedence for doing this via DominanceInfo. The reason I am
doing this is that I need the ownership verifier to be able to be run in Raw SIL
before no return folding has run. This means I need to be able to ignore
unreachable code resulting from SILGen not inserting unreachables after no
return functions.
The reason why SILGen does this is to preserve the source information of the
unreachable code so that we can emit nice errors about unreachable code.
rdar://29791263
(Headers first)
It has been generally agreed that we need to do this reorg, and now
seems like the perfect time. Some major pass reorganization is in the
works.
This does not have to be the final word on the matter. The consensus
among those working on the code is that it's much better than what we
had and a better starting point for future bike shedding.
Note that the previous organization was designed to allow separate
analysis and optimization libraries. It turns out this is an
artificial distinction and not an important goal.
