[clang] [Driver] Link Flang runtime on Solaris (PR #65644)

[Brad Smith via cfe-commits]

brad0 wrote:

> On top of that, Solaris `clang` doesn't handle `-r` correctly, passing `-e _start -Bdynamic` to `ld`, which makes it choke...

Looking at the GNU linker it seems to ignore -Bdynamic once -r is specified. Not sure how LLD handles things. The OpenBSD driver might need adjustments for the same thing.

https://github.com/llvm/llvm-project/pull/65644