swift

efa9f9eb - Optimizer: rewrite and improve the ConstantCapturePropagation pass

Optimizer: rewrite and improve the ConstantCapturePropagation pass (old name: CapturePropagation) The pass is now rewritten in swift which makes the code smaller and simpler. Compared to the old pass it has two improvements: * It can constant propagate whole structs (and not only builtin literals). This is important for propagating "real" Swift constants which have a struct type of e.g. `Int`. * It constant propagates keypaths even if there are other non-constant closure captures which are not propagated. This is something the old pass didn't do. rdar://151185177