[llvm] [ORC] Do not set CodeModel::Small in LLJITBuilder if JTMB already has a value (#88115) (PR #90599)

[Lang Hames via llvm-commits]

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

LGTM. Thanks very much @epitavy! (And apologies for the delay on the review)

https://github.com/llvm/llvm-project/pull/90599