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

[Alexander Kornienko via cfe-commits]

alexfh wrote:

I looked at the original code and found a much more involved expression there (https://gitlab.com/libeigen/eigen/-/blob/master/Eigen/src/Core/util/ForwardDeclarations.h?ref_type=heads#L66), so the parenthesized expression is merely an artifact of reduction and there doesn't seem to be an easy workaround, IIUC.

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