Log Message:
PC6001VX: update to 3.5.0.

pkgsrc changes:
- add workaround to avoid coredump by Q_ASSERT() when LANG is not set
  on Qt 5.14.1 that could return empty uiLanguages()

Upstream changes:

3.5.0 2020/06/07
- Updated PC-6001 compatible basic ROMs to 0.7.1.
- Updated PC-6001mk2/6601 compatible basic ROMs to 0.3.0.
- Enabled PC-6001mk2 model in compatible ROM mode.
- Added "Speed control" menu.
- In "File" and "Folder" tab on configuration dialog path \ 
which does not
  exist is displayed in red color.
- (Windows) Fixed issue that emulator continues to work during menu popup.