swift234

SIL: Add uncurry level to SILType.

We want to port CallEmission to the SIL level to handle uncurrying, but IRGen needs to have the original signature of a function available to it so that it can maintain the correct calling convention for different ABIs independent of SIL. Instead of flattening curried function types in SIL and losing that information, add an uncurryLevel to SILType so it can represent the type of an entry point at a given uncurry level. Unfortunately, this makes SILType outgrow a single word, so the way Value unions SILType and SILTypeList folding sets needs to be tweaked too.

Swift SVN r4345