Log Message:
xa65: update to 2.3.12.

Version 2.3.12 (26 November 2020)

What's new in 2.3.12:

- Regression fix for address size validation in 65816 mode (thanks Sam
  Falvo; we had a pending fix for this but I like his test case).
- Testsuite expanded.
- Because this is likely to be the final 2.3 release, the -x, -S and old
  mvn/mvp $xxxx syntax will be only supported in 2.3.10 through 2.3.12.
  It will be removed in 2.4 and up. You are warned!