[llvm] [WPD]Regard unreachable function as a possible devirtualizable target (PR #115668)

[Mingming Liu via llvm-commits]

minglotus-6 wrote:

I didn't find a test failure in the buildkite log (with `cat <buildkite>.log | grep -B 10 -A 10  "Failed Tests "`).

Local tests pass. Will merge.

https://github.com/llvm/llvm-project/pull/115668