git: 61e1a12bb6c3..0ff539eb7ca5 - vendor/bc - vendor branch updated

[Stefan Eßer]

The branch vendor/bc has been updated by se:

URL: https://cgit.FreeBSD.org/src/log/?id=61e1a12bb6c3..0ff539eb7ca5

0ff539eb7ca5 vendor/bc: import version 6.4.0