When extending a coroutine, handle the end_borrow instruction used to end a coroutine lifetime at a dead-end block. Fixes rdar://153479358 (Compiler crash when force-unwrapping optional ~Copyable type) (cherry picked from commit 5b5f370ce1)
5b5f370ce1
...byWalkingDown
initialWalkingDirection
is_escaping_closure
destroy_not_escaped_closure
dealloc_stack
alloc_stack
UseList
SingleValueInstruction.replace(with:)
copy_addr
store