Stop promoting type alignment by default

What is the feature you'd like to have?
There are some situations where we promote type alignment for a structure automatically. We should not do this.

Is your feature request related to a problem?
This can be problematic in cases where it causes padding bytes to be hidden. Because the padding bytes are hidden, you can't easily define a new member there without also undefining the prior member(s) to get the padding bytes to show up again.

Are any alternative solutions acceptable?
We could also just not hide the padding bytes at all (or provide an option to always show them). But, it's very nice to have them hidden in contexts where you have set the alignment and the fact that alignment can change on you without explicitly setting it feels strange and unexpected.

Additional Information:
This was reported by a customer today in a user feedback meeting we had with them.

Start by locating the C++ API code that promotes type alignment for structures and inspect how that behavior affects padding-byte visibility. The change is done when alignment is no longer promoted by default, while explicitly configured alignment can still provide the existing padding-hiding behavior.