swift234

SILGen: Emit curry thunks for standalone functions

For non-generic, non-property, non-instance-method curried functions, emit SIL thunks for all of the intermediate curry levels. The generic, property, and instance method cases need some additional SIL and irgen work to support, but aren't well supported by the current backend, so I'll leave them to be dealt with later. This causes the SliceUInt8 test to break down in IRGen; I'll fix that next.

Swift SVN r4715