Add 20222-data-bank to regression test suite. This exercises handling
of 16-bit operands with inter- and intra-bank references, and tests the
smartness in "smart PLB".
Also, update a couple of older tests that broke because the DBR is no
longer always the same as the PBR. This just required adding "B=K"
in a few places to restore the original output.
On the 65816, 16-bit data access instructions (e.g. LDA abs) are
expanded to 24 bits by merging in the Data Bank Register (B). The
value of the register is difficult to determine via static analysis,
so we need a way to annotate the disassembly with the correct value.
Without this, the mapping of address to file offset will sometimes
be incorrect.
This change adds the basic data structures and "fixup" function, a
functional but incomplete editor, and source for a new test case.
