SIL: don't treat debug uses of interior pointers as lifetime uses
The ownership verifier adds the transitive uses of an interior pointer as
implicit regular users of the enclosing borrow scope. Those uses come from
`findInnerTransitiveGuaranteedUses`, which reports `DebugUse` operands as leaf
use points, so a `debug_value` outside the borrow scope was diagnosed as
"Found outside of lifetime use". A debug use does not require its operand
to be alive, and the verifier already filters `DebugUse` from the uses it
gathers directly.
`checkScopedAddressUses` had the same hole for `store_borrow` scopes.
Fixes a false ownership verifier error.
