swift234

SILGen: Don't +1 'self' references for direct property access in constructors.

The CALayer brittleness in <rdar://problem/17014037> is worse than we thought—we can't r/r *at all* before super.init. Go through some contortions to ensure that, when doing direct stored property access in an initializer, we always base off of a +0 value. I tried fixing this in a more general and principled way using SGFContext::AllowPlusZero, but that introduced miscompiles we don't have the luxury of tracking down right now, so hack a more targeted fix that only affects class initializers.

Swift SVN r18635