swift234

Make transparent inlining apply transparency recursively to all calls and also see through applications of partial applications (in SSA form); this is intended to ensure that [auto_closure] arguments of [transparent] functions get inlined, although that's additionally blocked by (apparent?) incompleteness of SSA-ification passes currently and phase ordering issues.

After implementing this I realized that a lot of the logic currently in MandatoryInlining.cpp should be moved into the SILInliner so it can be reused in an optimizing inliner. I plan on doing that refactoring immediately but decided to go ahead and commit this since it's a working incremental step.

Swift SVN r7771