Variables are now handled properly end-to-end, except for label
uniquification. So cc65 and ACME can't yet handle a file that
redefines a local variable.
This required a bunch of plumbing, but I think it came out okay.
Still primarily ascending numeric order, but now we use the symbol
type as the secondary sort instead of the label.
Also, fix References crash on first line of empty var table.
We now generate FormatDescriptors with WeakSymbolRefs for direct
page references that match variable table entries.
LocalVariableTable got a rewrite. We need to be unique in both
name and address, but for the address we have to take the width into
account as well. We also want to sort the display by address
rather than name. (Some people might want it sorted by name, but
we can worry about that some other time.)
Updated the DefSymbol editor to require value uniqueness. Note
addresses and constants exist in separate namespaces.
The various symbols are added to the SymbolTable so that uniqueness
checks work correctly. This also allows the operand generation to
appear to work, but it doesn't yet handle redefinition of symbols.
Multi-line item, with one .eq line per variable definition. Add
one header line if "clear previous" is set.
Also, limit variable values to 0-255 in the editor. This is
somewhat arbitrary, but I think a focus on DP is useful.
The table editor is now editing the table, and the DefSymbol editor
now asks for the Width data when editing a local var.
This also moves EditDefSymbol closer to proper WPF style, with
bound properties for the input fields.
No changes yet to serialization or analysis.
