swift234

SILGen: Implement r/r of fragile aggregates.
Stick a ReferenceTypeElements array in the SIL TypeInfo that gives a path to every reference type within a fragile aggregate. Since this now makes TypeInfo nontrivial to compute, steal some of the TypeConverter infrastructure from IRGen to manage TypeInfos for the current SILGen context. Use the reference type elements to determine triviality and to generate retain/release sequences for nontrivial loadable types.

Swift SVN r3301