swift234

SILGen: Implement reftype elements and properties.
Generalize a bunch of code that assumed address-of-value-type for the "this" side of properties to accept reftypes as well. Use RefElementAddrInst to extract physical elements of reference types. Fix an off-by-one in the writeback logic in emitStoreToLValue so that writeback chains properly terminate at the deepest value type component below a reference type component.

Swift SVN r3445