Work around clang-cl missing ldar, stlr

[Frank Richter (res2k)]

The problematic code paths are hit when using clang-cl in C mode.

Fall through to code paths not using.

Disclaimer: This was purely done to fix builds, I didn't check the extend this affects performance.

[Daan (daanx)]

Thanks Frank. I applied it to the dev branch instead, hope that is ok. Thanks again.

[Frank Richter (res2k)]

Thanks Frank. I applied it to the dev branch instead, hope that is ok. Thanks again.

Sure - I filed the PR against dev3 since I've seen this being an issue in 3.5.0.

[Daan (daanx)]

Ah, dev is upstream of both dev2 and dev3 so it'll flow in to dev3 already.
Generally, PR's should go against dev if it applies to all versions. (well, I am trying to only apply security and build fixes to dev and dev2 nowadays to keep them stable).
The other PR to add C/CXX tests to the workflow is ok to only do for dev3