Created the 20180-extension-scripts test by cutting out the handful
of 65816-specific items from 20182. Removed some issue-specific stuff
from 20182 that didn't need to be duplicated. Renamed some stale
references to test 2022.
We weren't altering the status flags after a BRK because of the
assumption that a BRK was a crash. For an inline BRK, such as a SOS
call, execution continues. We need to mark NVZC indeterminate or
we may incorrectly handle conditional branches that follow.
The BRK instruction now uses the same flag updater as JSR, since it's
effectively a subroutine call to unknown code. If execution doesn't
continue across the BRK then the flags don't matter.
Updated 20182-extension-scripts to exercise this.
Andy McFadden