[clang-tools-extra] [clang-tidy] Avoid assert failure on non-identifier names in `readability-container-size-empty` (PR #181557)

[Baranov Victor via cfe-commits]

vbvictor wrote:

> > Strangely, shouldn't we've hit this assert before? Release build must've silently suppressed it
> 
> It do seems weird... It is possible that we aren't using assertion builds for testing large codebases before.

We should make Release + assertions build on https://github.com/clang-tidy-infra/CTIT

https://github.com/llvm/llvm-project/pull/181557