[llvm] [Offload] add 'olIterateSymbols' runtime function (PR #213036)

[Nick Sarnie via llvm-commits]

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

lgtm, didn't review amdgpu changes and please wait for an approval from alex for the l0 part, thanks!

https://github.com/llvm/llvm-project/pull/213036