[clang] [Clang] Add 'CLANG_ALLOW_IMPLICIT_RPATH' to enable toolchain use of -rpath (PR #82004)

[Tom Stellard via cfe-commits]

tstellar wrote:

> We could make this logic more complicated by checking the system automatically `execute_command(lsb_release)` or something.

I think this is too complicated and fragile.  If we want to do something specifically to support the distro use case, I think we should do this: https://reviews.llvm.org/D142174


https://github.com/llvm/llvm-project/pull/82004