[clang] [llvm] [CMake][Release] Enable CMAKE_POSITION_INDEPENDENT_CODE (PR #90139)

[via llvm-commits]

llvmbot wrote:

<!--IGNORE-->
Failed to cherry-pick: 53ff002c6f7ec64a75ab0990b1314cc6b4bb67cf

https://github.com/llvm/llvm-project/actions/runs/8863031679

Please manually backport the fix and push it to your github fork.  Once this is done, please create a [pull request](https://github.com/llvm/llvm-project/compare)

https://github.com/llvm/llvm-project/pull/90139