Implemented assembly source generation of non-unique local labels.
The new 2023-non-unique-labels test exercises various edge cases
(though we're still missing local variable interaction).
The format of uniquified labels changed slightly, so the expected
output of 2012-label-localizer needed to be updated.
This changes the "no opcode mnemonics" and "mask leading underscores"
functions into integrated parts of the label localization process.
Update the symbol lookup in EditInstructionOperand, EditDataOperand,
and GotoBox to correctly deal with non-unique labels.
This is a little awkward because we're doing lookups by name on
a non-unique symbol, and must resolve the ambiguity. In the case of
an instruction operand that refers to an address this is pretty
straightforward. For partial bytes (LDA #>:foo) or data directives
(.DD1 :foo) we have to take a guess. We can probably make a more
informed guess than we currently are, e.g. the LDA case could find
the label that minimizes the adjustment, but I don't want to sink a
lot of time into this until I'm sure it'll be useful.
Data operands with multiple regions are something of a challenge,
but I'm not sure specifying a single symbol for multiple locations
is important.
The "goto" box just finds the match that's closest to the selection.
Unlike "find", it always grabs the closest, not the next one forward.
(Not sure if this is useful or confusing.)
Added serialization of non-unique labels to project files.
The address labels are stored without the non-unique tag, because we
can get that from the file offset. (If we stored it, we'd need to
extract the value and verify that it matches the offset.) Operand
weak references are symbolic, and so do include the tag string.
We weren't validating symbol labels before. Now we are.
This also adds a "NonU" filter to the Symbols window so the labels
can be shown or hidden as desired.
Also, added source for a first pass at a regression test.
