swift

88729b9e - [sending] Make {Transferring,Sending}ArgsAndResults a LANGUAGE_FEATURE instead of an UPCOMING_FEATURE.

[sending] Make {Transferring,Sending}ArgsAndResults a LANGUAGE_FEATURE instead of an UPCOMING_FEATURE. TLDR: This makes it so that we always can parse sending/transferring but changes the semantic language effects to be keyed on RegionBasedIsolation instead. ---- The key thing that makes this all work is that I changed all of the "special" semantic changes originally triggered on *ArgsAndResults to now be triggered based on RegionBasedIsolation being enabled. This makes a lot of sense since we want these semantic changes specifically to be combined with the checkers that RegionBasedIsolation turns on. As a result, even though this causes these two features to always be enabled, we just parse it but we do not use it for anything semantically. rdar://128961672