[llvm] [SLP]Improve minbitwidth analysis. (PR #84536)

[Martin Storsjö via llvm-commits]

mstorsjo wrote:

> AS I said, I'll revert it, better to commit fixed versions. Will revert ASAP.

Thanks, much appreciated!



> Think this also is causing a failure when building `llvm-test-suite` (which might be easier to reproduce):
> 
> ```
> FAILED: MultiSource/Benchmarks/MiBench/consumer-jpeg/CMakeFiles/consumer-jpeg.dir/jdsample.c.o 
> ```

I think this is the same issue as I had reduced above; building libjpeg (in some form) triggers failed asserts in `jdsample.c` and `jcsample.c`, the one above that I had reduced was from `jcsample.c`.

But the cases that trigger no asserts but produce wrong results at runtime are probably harder to sort out.



https://github.com/llvm/llvm-project/pull/84536