[clang-format] handle formatting on constexpr if

Hey all,

I was wondering if it was possible to include the proper formatting

of constexpr if in 4.0.1 ?

See this patch: http://lists.llvm.org/pipermail/cfe-dev

Best,

Nils

The link seems wrong?

Hey,

Sorry, here is the correct link

https://reviews.llvm.org/D26953