UI automation
# To move issue-3154 and issue-16774 to functional subdirectories:
I have moved 2 tests from tests/ui/issues to their appropriate directories using "test-manager" tool.
## Changes:
- Moved tests/ui/issues/issue-3154.rs to tests/ui/borrowck/missing-lifetime-in-return.rs
- Moved tests/ui/issues/issue-16774.rs to tests/ui/deref/derefmut-closure-drop-order.rs
These moves where performed using the test-manager automation tool.
Jonathan Brouwer