[clang] [Driver] Handle Flang in same manner between Gnu and *BSD/Solaris ToolChain (PR #70429)

[Brad Smith via cfe-commits]

brad0 wrote:

So with https://github.com/llvm/llvm-project/pull/72601, once that goes in I can update this with RUN line updates to test. It fails as expected without this.

https://github.com/llvm/llvm-project/pull/70429