[llvm] [VPlan] Update final IV exit value via VPlan. (PR #112147)

[LLVM Continuous Integration via llvm-commits]

llvm-ci wrote:

LLVM Buildbot has detected a new failure on builder `llvm-clang-aarch64-darwin` running on `doug-worker-4` while building `llvm` at step 6 "test-build-unified-tree-check-all".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/190/builds/13088

<details>
<summary>Here is the relevant piece of the build log for the reference</summary>

```
Step 6 (test-build-unified-tree-check-all) failure: test (failure)
******************** TEST 'lit :: reorder.py' FAILED ********************
Exit Code: 1

Command Output (stdout):
--
# RUN: at line 3
cp Inputs/reorder/lit_test_times Inputs/reorder/.lit_test_times.txt
# executed command: cp Inputs/reorder/lit_test_times Inputs/reorder/.lit_test_times.txt
# .---command stderr------------
# | cp: Inputs/reorder/.lit_test_times.txt: No space left on device
# `-----------------------------
# error: command failed with exit status: 1

--

********************


```

</details>

https://github.com/llvm/llvm-project/pull/112147