[llvm] [llvm-cov] let text mode divider honor `--show-branch-summary` `--show-region-summary` etc (PR #96016)

[Hana Dusíková via llvm-commits]

https://github.com/hanickadot requested changes to this pull request.

You need to fix tests for things you changed in llvm-cov.

https://github.com/llvm/llvm-project/pull/96016