[llvm] [mi-sched] Suppress register pressure with i64. (PR #88256)

[Pengcheng Wang via llvm-commits]

https://github.com/wangpc-pp approved this pull request.

LGTM though I think this existed traversal of all int VTs is kind of silly, but I don't figure out a better way now.

https://github.com/llvm/llvm-project/pull/88256