[llvm] Revert "[LoongArch] Remove spurious mask operations from andn->icmp on 16 and 8 bit values" (PR #99792)

[LLVM Continuous Integration via llvm-commits]

llvm-ci wrote:

LLVM Buildbot has detected a new failure on builder `clang-aarch64-lld-2stage` running on `linaro-clang-aarch64-lld-2stage` while building `llvm` at step 7 "ninja check 1".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/121/builds/300

Here is the relevant piece of the build log for the reference:
```
Step 7 (ninja check 1) failure: 1200 seconds without output running [b'ninja', b'check-all'], attempting to kill
...
PASS: lit :: usage.py (82478 of 82488)
PASS: lit :: shtest-not.py (82479 of 82488)
PASS: lit :: use-llvm-tool.py (82480 of 82488)
PASS: lit :: discovery.py (82481 of 82488)
PASS: lit :: xfail-cl.py (82482 of 82488)
PASS: lit :: max-time.py (82483 of 82488)
PASS: lit :: shtest-timeout.py (82484 of 82488)
PASS: lit :: selecting.py (82485 of 82488)
PASS: lit :: shtest-define.py (82486 of 82488)
PASS: lit :: shtest-shell.py (82487 of 82488)
command timed out: 1200 seconds without output running [b'ninja', b'check-all'], attempting to kill
process killed by signal 9
program finished with exit code -1
elapsedTime=2471.922725

```

https://github.com/llvm/llvm-project/pull/99792