[Test] Adapted test to different borrow scopes.
Borrow scopes were moved when lexical borrow scopes were no longer
emitted for owned arguments. Now, they are emitted when guaranteed
values are needed. Fixing these diagnostics will be tracked separately.
The same issue is already visible elsewhere in this test file, e.g. in
castTestSwitch1, castTestSwitch2, and castTestSwitchInLoop.
