[clang] [clang-repl] Fix BUILD_SHARED_LIBS symbols from libclangInterpreter on MinGW (PR #71393)

[Jun Zhang via cfe-commits]

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

Thanks for the fix! I'm fine with it if this fixes your problem. But yeah, please make sure @vgvassilev is aware of it.

https://github.com/llvm/llvm-project/pull/71393