[llvm] Add CMake configure preset building blocks (PR #170019)

[Richard Thomson via llvm-commits]

LegalizeAdulthood wrote:

> It'd be useful to expand the set of presets to cover all common configurations but I'm fine with this as a starting point.

My hope is that an existing starter set will motivate others to contribute and/or discuss common building blocks that can be used by others.  My familiarity is with clang-tidy and the common sets of options used when working there.  I'm not aware of a way to embed a comment in a CMake preset, or I would have added one explaining the rationale/usage.

Once this PR lands, I intend to create another PR that updates the clang-tidy developer docs to discuss how to use these presets in a user's custom preset.

https://github.com/llvm/llvm-project/pull/170019