go: all: Go bootstrap on FreeBSD/386 failed with "signal: trace/BPT trap"

Go bootstrap from source failed on FreeBSD/386 with default configured max locked memory 64K, passed when increase to 256K.

May be this is not a bug of Go?

more detail: https://groups.google.com/forum/#!topic/golang-dev/HZJaDukLCuA

Please answer these questions before submitting your issue. Thanks!

What version of Go are you using (go version)?

go version devel +cd0ba4c Wed Aug 31 23:22:53 2016 +0000 freebsd/386

What operating system and processor architecture are you using (go env)?

GOARCH="386"
GOBIN=""
GOEXE=""
GOHOSTARCH="386"
GOHOSTOS="freebsd"
GOOS="freebsd"
GOPATH="/home/rhinofly/home/sandspace/extpkg/"
GORACE=""
GOROOT="/home/rhinofly/home/sandspace/go"
GOTOOLDIR="/home/rhinofly/home/sandspace/go/pkg/tool/freebsd_386"
CC="clang"
GOGCCFLAGS="-fPIC -m32 -fno-caret-diagnostics -Qunused-arguments -fmessage-length=0 -fdebug-prefix-map=/home/rhinofly/home/sandspace/tmp/go-build328284812=/tmp/go-build -gno-record-gcc-switches"
CXX="clang++"
CGO_ENABLED="0"

What did you do?

If possible, provide a recipe for reproducing the error. A complete runnable program is good. A link on play.golang.org is best.

bootstrap from source:

git clone https://github.com/golang/go.git && cd go/src && ./all.bash

What did you expect to see?

ALL TESTS PASSED

What did you see instead?

##### ../test/bench/go1
testing: warning: no tests to run
PASS
ok      _/home/rhinofly/sandspace/official-go/test/bench/go1    50.154s

##### ../test
# go run run.go -- fixedbugs/issue11286.go
exit status 1
signal: trace/BPT trap

FAIL    fixedbugs/issue11286.go 3.592s
2016/09/01 18:26:59 Failed: exit status 1
# go run run.go -- fixedbugs/bug024.go
exit status 1
go build command-line-arguments: /home/rhinofly/home/sandspace/official-go/pkg/tool/freebsd_386/compile: signal: trace/BPT trap

FAIL    fixedbugs/bug024.go 0.185s

##### API check
skipped due to earlier error
2016/09/01 18:27:08 Failed: exit status 1
2016/09/01 18:27:08 FAILED