[llvm] [SCEV] Introduce exact flag for UDiv (PR #225065)

[via llvm-commits]

github-actions[bot] wrote:

test-suite diff from 08d36e8388141b79783b77236041d5846bb0bc22...8c5ec8a298505fa8dc85cacbfb79323b17077eb6: https://github.com/llvm/llvm-project/actions/runs/36679550151/artifacts/11087017222

Statistics: https://github.com/llvm/llvm-project/actions/runs/36679550151/artifacts/11086907842

## riscv64-linux-gnu `-march=rva23u64 -O3`
| ('Program', '')    |   ('size..text', 'base') |   ('size..text', 'head') |   ('size..text', 'diff') |
|:-------------------|-------------------------:|-------------------------:|-------------------------:|
| Geomean difference |                      nan |                      nan |                        0 |
## aarch64-linux-gnu `-march=armv9-a -O3`
| ('Program', '')    |   ('size..text', 'base') |   ('size..text', 'head') |   ('size..text', 'diff') |
|:-------------------|-------------------------:|-------------------------:|-------------------------:|
| Geomean difference |                      nan |                      nan |                        0 |
## x86_64-linux-gnu `-march=x86-64-v3 -O3`
| ('Program', '')    |   ('size..text', 'base') |   ('size..text', 'head') |   ('size..text', 'diff') |
|:-------------------|-------------------------:|-------------------------:|-------------------------:|
| Geomean difference |                      nan |                      nan |                        0 |


https://github.com/llvm/llvm-project/pull/225065