[llvm] [llvm-readtapi] Add install-distribution support (PR #67748)

[Juergen Ributzka via llvm-commits]

ributzka wrote:

I am looking at `llvm-nm` as an example, which also has the symlink. `llvm-nm` is also part of LLVM_TOOLCHAIN_TOOLS, but I don't see `llvm-readtapi` in that list.

https://github.com/llvm/llvm-project/pull/67748