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

[David Spickett via cfe-commits]

DavidSpickett wrote:

The flang failure also came up on Linaro's 2 stage bots: https://lab.llvm.org/buildbot/#/builders/4/builds/1670

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