all: add freebsd/riscv64 support

[P1umer]

---

Before sending a pull request, please review Contribution Guidelines: https://github.com/google/syzkaller/blob/master/docs/contributing.md

---

[codecov[bot]]

Codecov Report

Merging #3253 (91ad1f1) into master (ab32d50) will decrease coverage by 0.6%. The diff coverage is n/a.

:exclamation: Current head 91ad1f1 differs from pull request most recent head 55eef4c. Consider uploading reports for the commit 55eef4c to get more accurate results

Impacted Files	Coverage Δ
pkg/compiler/const_file.go	66.5% <ø> (ø)
pkg/email/patch.go	82.8% <0.0%> (-11.3%)	:arrow_down:
pkg/vcs/linux.go	18.1% <0.0%> (-6.4%)	:arrow_down:
dashboard/app/reporting_email.go	58.1% <0.0%> (-5.8%)	:arrow_down:
prog/test_util.go	54.7% <0.0%> (-3.9%)	:arrow_down:
pkg/ipc/ipc.go	49.1% <0.0%> (-3.8%)	:arrow_down:
pkg/csource/build.go	47.4% <0.0%> (-3.5%)	:arrow_down:
dashboard/app/graphs.go	45.7% <0.0%> (-3.2%)	:arrow_down:
pkg/email/parser.go	76.9% <0.0%> (-3.2%)	:arrow_down:
dashboard/app/jobs.go	63.4% <0.0%> (-1.9%)	:arrow_down:
... and 69 more

[dvyukov]

Conflicting files go.mod

Please rebased to master HEAD to resolve the conflict.

[dvyukov]

Github still says:

This branch has conflicts that must be resolved
Conflicting files
go.mod
go.sum
vendor/golang.org/x/sys/unix/ioctl_linux.go
vendor/golang.org/x/sys/unix/syscall_linux.go
vendor/golang.org/x/sys/unix/syscall_solaris.go
vendor/modules.txt

[a-nogikh]

Hi!

Is the PR in a ready-to-merge state now? I think we might need to update vendors once more after rebasing.

[P1umer]

Have updated vendor after rebasing.

[a-nogikh]

Merged, thanks!