Replace our check dialect with upstreaming to RunnerUtils.cpp

[rengolin]

RunnerUtils.cpp already has verifiers that we can use for equality.

Instead of adding a new dialect, I think we just need a local utility builder that can lower to the right runtime calls (and declare them in IR). But to get the almost_equals logic, we'll need to upstream that part. We need this for existing types and bf16 too (both verify and almost_equals).

It should be trivial to just follow the existing pattern and add this functionality upstream, then change out test to use the new style, removing the check dialect from the picture.

While we're at it, we could also add a printMemrefBF16 variant...

@KavithaTipturMadhu