swift

1dcf271f - SIL: Treat store_borrow as borrowing its source, and have the move-only checker account for borrow scopes.

SIL: Treat store_borrow as borrowing its source, and have the move-only checker account for borrow scopes. When rewriting uses of a noncopyable value, the move-only checker failed to take into account the scope of borrowing uses when establishing the final lifetimes of values. One way this manifested was when borrowed values get reabstracted from value to in-memory representations, using a store_borrow instruction, the lifetime of the original borrow would be ended immediately after the store_borrow begins rather than after the matching end_borrow. Fix this by, first, changing `store_borrow` to be treated as a borrowing use of its source rather than an interior-pointer use; this should be more accurate overall since `store_borrow` borrows the entire source value for a well-scoped duration balanced by `end_borrow` instructions. That done, change MoveOnlyBorrowToDestructureUtils so that when it sees a borrow use, it ends the borrow at the end(s) of the use's borrow scope, instead of immediately after the beginning of the use.