[flang] [clang] [flang][driver] add -flang-deprecated-no-hlfir hidden option (PR #71820)

[Tom Eccles via cfe-commits]

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

> Thanks for the review @tblah. I could not find flang/test/HLFIR/hlfir-flang.f90 test, did you mean flang/test/HLFIR/hlfir-**flags**.f90 (in which case it is updated in this PR already).

Yes I meant hlfir-flags.f90. Sorry about that. Thanks for the changes!

https://github.com/llvm/llvm-project/pull/71820