[llvm] [NFC][DebugInfo] Deprecate iterator-taking moveBefore and getFirstNonPHI (PR #124290)

[Jeremy Morse via llvm-commits]

jmorse wrote:

I understand MSVC isn't enjoying the deprecated-function-calls-a-deprecated-function pattern, which gcc and clang don't complain about. I'll have a patch for this shortly.

https://github.com/llvm/llvm-project/pull/124290