[clang-tools-extra] [Clang-Tidy] Add google-runtime-float Clang-Tidy check (PR #156763)

[Baranov Victor via cfe-commits]

vbvictor wrote:

> > I think this can go straight into `portability`. Also linking this recent related PR: #146970.
> 
> It could go there and then have an alias to `google` if wanted maybe? 

I'm weak +1 on this, `portability-avoid-long-double` maybe?
But if anything happens, we could add alias later.


https://github.com/llvm/llvm-project/pull/156763