runtime: enable race detector on openbsd/amd64

Now that this commit[1] has landed in LLVM the .syso file can be generated for
OpenBSD.

With the changes to src/runtime running the sample race[2] detects the data
race as expected.

Based on golang/go#39464 (https://go-review.googlesource.com/c/go/+/237057) from
Aaron Bieber <deftly@gmail.com>, however the race_openbsd_amd64.syso file has
been built on OpenBSD 6.4 and necessary changes added to race.bash.

[1] https://github.com/llvm/llvm-project/commit/fcf6ae2f070eba73074b6ec8d8281e54d29dbeeb
[2] https://golang.org/doc/articles/race_detector.html

Change-Id: Ic2479ccfa91d6b2cb4585346a11d813d96450f68
Reviewed-on: https://go-review.googlesource.com/c/go/+/275892
Trust: Joel Sing <joel@sing.id.au>
Run-TryBot: Joel Sing <joel@sing.id.au>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>

1 files changed, 6 insertions, 1 deletions

diff --git a/src/race.bash b/src/race.bash
index e2b96bcffe..81fb4be606 100755
--- a/src/race.bash
+++ b/src/race.bash
@@ -9,7 +9,7 @@
 set -e
 
 function usage {
-	echo 'race detector is only supported on linux/amd64, linux/ppc64le, linux/arm64, freebsd/amd64, netbsd/amd64, darwin/amd64, and darwin/arm64' 1>&2
+	echo 'race detector is only supported on linux/amd64, linux/ppc64le, linux/arm64, freebsd/amd64, netbsd/amd64, openbsd/amd64, darwin/amd64, and darwin/arm64' 1>&2
 	exit 1
 }
 
@@ -34,6 +34,11 @@ case $(uname) in
 		usage
 	fi
 	;;
+"OpenBSD")
+	if [ $(uname -m) != "amd64" ]; then
+		usage
+	fi
+	;;
 *)
 	usage
 	;;