[clang] [clang] check deduction consistency when partial ordering function templates (PR #100692)

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cor3ntin wrote:

@mizvekov please avoid force pushing (prefer merging from main and push new commits) - otherwise github sometimes
eat comments which makes review difficult.

I previously mentioned that your changes to `getMoreSpecializedTemplate` probably needed explicit object parameters tests. I then realized that this was https://www.open-std.org/jtc1/sc22/wg21/docs/cwg_active.html#2834. Can you check what we do in this case? Thanks

https://github.com/llvm/llvm-project/pull/100692