For some errors, we use the unroll logic to get the list of required
arguments. The usage then does the same, but without a matcher. This
was causing the lists to not match.
As a side effect, this fixed an ordering issue where we were putting the
present arg after the not-present arg. I assume its because we ended up
reporting the items twice but the first time is correctly ordered and
gets precedence.
This was split out of #3020
This is prep for moving the derive tests. Besides organizing the test
folder for each API, this should reduce link time at the cost of
re-compiling more when a test changes.
