[llvm] [NFC] Change FindDbgDeclareUsers interface to match findDbgUsers/values (PR #73498)

[Jeremy Morse via llvm-commits]

https://github.com/jmorse approved this pull request.

LGTM as a mechanical change; could I suggest using SmallVector with an explicit size of 1 rather than the default. I think the default will allocate ~64 bytes on the stack for elements, wheras the TinyPtrVector that you're replacing is designed to handle zero-or-one elements. This change will result in more space being used on the stack, but we can limit it to about an extra 8 bytes instead of an extra 64.

https://github.com/llvm/llvm-project/pull/73498