swift234

Fix rdar://15492647 - destroy_addr dropped by DI, causing leaks

Fix DI to not delete non-trivial memory allocations that are still 
used by destroy_addr or strong_release, since just dropping those operations
will cause a memory leak.

This is simple, but prevents DI from removing most allocations.  To
avoid having to update all the testcases :), teach it also to promote
non-address-only destroy_addrs into a load+release sequence when the
load's value is available, as part of normal load promotion.



Swift SVN r10542