Commits
Andrew Trick committed dae2922467a
To preserve source level copies, is_unique must appear to decrement the refcount of its object. Fixes <rdar://problem/20901275> Optimize retain/release across is_unique when the pointer cannot alias. This is not a regression, but was something that adding SIL is_unique is supposed to fix. However, that required making ARC optimization more conservative. Unfortunately it is necessary for correctness. We can improve the situation later with more advanced analysis: <rdar://problem/20901275> Optimize retain/release across is_unique when the pointer cannot alias Swift SVN r28438