If a symbol is defined at <addr>, and we counter STA <addr>-1,Y,
we want to use the symbol in the operand. This worked for labels
but not project/platform symbols.
Also, fixed a crash that happened if you tried to delete an auto
label.
There are some useful interactions between C/N and maybe Z. Added
a quick test to 1003-flags-and-branches.
Also, updated the 2008-address-changes tests. Change b37d3dba
extended the nearby-target range of out-of-file symbols by one, so
one line that didn't get an operand label now does.