Most assemblers end local label scope when a global label is
encountered. cc65 takes this one step further by ending local label
scope when constants or variables are defined. So, if we have a
variable table with a nonzero number of entries, we want to create
a fake global label at that point to end the scope.
Merlin 32 won't let you write " LDA #',' ". For some reason the
comma causes an error. IGenerator now has a "tweak operand format"
interface that lets us fix that.
This hits most of the edge cases, but doesn't exercise the two
duplicate name situations (var name same as user label, var name
same as project/platform symbol).
Also, fixed a bug in the EditDefSymbol uniqueness check where it
was comparing a symbol to itself.
