[Flang][Driver] Add regex support for R_Group options

Add regex handling for all variations of OPT_R_Joined, i.e.
`-Rpass`, `-Rpass-analysis`, `-Rpass-missed`.

Depends on D158174. That patch implements backend support for
R_Group options.

Reviewed By: awarzynski

Differential Revision: https://reviews.llvm.org/D158436