This spreads out transitively to many places and requires that
we use `check_call!` instead of `check_one_call` in a number of
places.
(cherry picked from commit 6bc31dcf206518a7be7f0ac6e773d5dfe25531ea)
The mutation-based methods had some pitfalls, and we don't really
need them.
We could re-add them if we need to.
(cherry picked from commit ca92b8491d87cebf54dd2468599168fc7a16c07f)
This is slightly easier to use than the previous pattern that was
always followed up by the same conversions.
(cherry picked from commit 756c080730cd4fa81d4c0e3a99688cbe8debe57f)
