swift234

SIL: Release arguments and retain stores to boxes.
Build some infrastructure for handling retain/release/copy/destroy of values. Use this to retain values when storing them into boxes and to clean up reference type arguments on function exit. Right now this just stupidly assumes "value type is trivial, reference type is retained/released", but it eventually needs to handle address-only types using the indirect copy_addr/destroy_addr instructions and to handle loadable value types with reference members by retaining the proper members. Passing arguments to function calls, reassignment, and cleanup of full expression temporaries all still need implementation.

Swift SVN r3267