[clang] [flang] [clang][Driver] Add RPATH by default (PR #115286)

[David Truby via cfe-commits]

DavidTruby wrote:

It's also of course possible to have this as the sensible default (making clang+openmp work out of the box, making flang work out of the box etc) and expect people wanting the opposite to use config files to add `-fno-rtlib-add-rpath`. I guess that it's possible that this would be a breaking change for CMake though, which would be bad. 

https://github.com/llvm/llvm-project/pull/115286