swift

a7422b7a - [sil.rst] Add a discussion of "Dead End Blocks" and its implications upon OSSA.

[sil.rst] Add a discussion of "Dead End Blocks" and its implications upon OSSA. The main implication being that we allow for values to be leaked along dead end blocks. NOTE: For those who are unaware, a dead end block in SIL is a block that is post-dominated in the same function by program terminating blocks (which we model using unreachables).