The tests complete in 3 seconds on my amd64 system.
I do assume that the 100 times slower execition on riscv64 is due to inefficient emulation of that platform?
Instead of patching the timeout in individual ports, I believe the parameters in the CI system should be adjusted to account for the slow execution speed of emulated systems.
Therefore, I do not want to set the timeout to such a high value for all platforms.
If there is consensus that changing individual ports is required, I'd make the timeout adjustment depend on the architecture (apparently, only riscv64 is affected).

Looks fine.

Update diff to be in standard format (had been created with "diff.mnemonicprefix=true").

In D46876#1068975, @emaste wrote:

phabricator tagged it with "does not need to be reviewed"

Phabricator recognizes it as a generated file and so doesn't need to be reviewed. The note is intended more for the assigned reviewers - the change can be included, Phab just notes that reviewers don't need to look at it.

Address review comments.

In D46876#1068925, @des wrote:

You also need to remove tools/build/options/WITH_GH_BC, move the relevant section of tools/build/mk/OptionalObsoleteFiles.inc to ObsoleteFiles.inc, and regenerate share/man/man5/src.conf.5.

In D46876#1068928, @des wrote:

In D46876#1068845, @emaste wrote:

Is there value in keeping the tests that were added to the old version?

Perhaps. More importantly, Gavin Howard's bc has its own test suite which we could adopt. Take a look at how Apple did it: https://github.com/apple-oss-distributions/bc

Update diff to include removal of dependency on MK_GH_BC from usr.bin/Makefile and from tools/build/mk/OptionalObsoleteFiles.inc.