Revert rest of `IRBuilderBase`'s short-circuiting folds

Upon further investigation and discussion,
this is actually the opposite direction from what we should be taking,
and this direction wouldn't solve the motivational problem anyway.

Additionally, some more (polly) tests have escaped being updated.
So, let's just take a step back here.

This reverts commit f3190ded.
This reverts commit 749581d2.
This reverts commit f3df87d5.
This reverts commit ab1dbcec.