[llvm] [X86][TargetLowering] Avoid deleting temporary nodes in `getNegatedExpression` (PR #139029)

[via llvm-commits]

wjristow wrote:

The fix LGTM, and I can confirm it fixes my original, un-reduced test-case.

I don't have an opinion on:
>`std::optional<HandleSDNode> Handles[3]` may be better.

https://github.com/llvm/llvm-project/pull/139029