[clang] [analyzer][Solver] Early return if sym is concrete on assuming (PR #115579)

[Balazs Benics via cfe-commits]

https://github.com/steakhal approved this pull request.

LGTM now. Thank you for this high quality patch. This isn't the first time, I remember. Excellent track record.

https://github.com/llvm/llvm-project/pull/115579