[llvm] [SLP] Prefer immediate opcode matches on score ties (PR #225869)

[via llvm-commits]

github-actions[bot] wrote:

test-suite diff from d4afeda893d3b7b70101f90bc3ec76a31154b0be...2a7d09fe85dd1832d58f0a4d65f7d71725687fee: https://github.com/llvm/llvm-project/actions/runs/35900241415/artifacts/10773012439

Statistics: https://github.com/llvm/llvm-project/actions/runs/35900241415/artifacts/10773950306

## 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 |             -9.14364e-05 |


https://github.com/llvm/llvm-project/pull/225869