We already have the warning "Incomplete 'switch' cases on enum" enabled,
but it does not warn when a case is missing if the switch has a default
block.
Enable the "Signal even if 'default' case exists" option. This would
have enabled us to catch the problem that was fixed in Ied8ff0f8f.
In most instances of the warning we can simply add the missing case(s)
above the 'default', meaning there is no change in behaviour.
However there are some instances where the missing case is a bug and
should be handled correctly. These are fixed separately in follow-up
commits.
Change-Id: I3675d29981423043266a26b1a78932c5708a6272
0b7517a06e