[llvm] [LV] Only require a scalar epilogue for interleave groups actually widened as interleave accesses (PR #213904)

[via llvm-commits]

github-actions[bot] wrote:

<!--PREMERGE ADVISOR COMMENT: Windows-->
# :window: Windows x64 Test Results

* 139235 tests passed
* 3621 tests skipped
* 1 test failed

## Failed Tests
(click on a test name to see its output)

### LLVM-Unit
<details>
<summary>LLVM-Unit.Transforms/Vectorize/_/VectorizeTests_exe/VPlanHCFGTest/testBuildHCFGInnerLoopMultiExit</summary>

```
Script:
--
C:\_work\llvm-project\llvm-project\build\unittests\Transforms\Vectorize\.\VectorizeTests.exe --gtest_filter=VPlanHCFGTest.testBuildHCFGInnerLoopMultiExit
--
unknown file
SEH exception with code 0x3221225501 thrown in the test body.
Stack trace:



```
</details>

If these failures are unrelated to your changes (for example tests are broken or flaky at HEAD), please open an issue at https://github.com/llvm/llvm-project/issues and add the `infrastructure` label.

https://github.com/llvm/llvm-project/pull/213904