[clang] [lldb] [llvm] [cmake] Build executables with -no_exported_symbols when building Apple toolchain (PR #87684)

[Dan Liew via cfe-commits]

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

Generally looks good. I have some minor nits. I'd like to see `LLVM_ENABLE_EXPORTED_SYMBOLS` renamed to avoid ambiguity.

https://github.com/llvm/llvm-project/pull/87684