runtime: TestDebugCall* flaky on android-amd64-emu

[bcmills]

From the android-amd64-emu builder (https://build.golang.org/log/9cf7d64a00c151574d96c45a0b6e50358b527085):

##### GOMAXPROCS=2 runtime -cpu=1,2,4 -quick
--- FAIL: TestDebugCallPanic (0.01s)
    debug_test.go:244: executing on Go runtime stack
FAIL
exitcode=1FAIL	runtime	31.768s

CC @aclements @mknyszek

[bcmills]

A very similar failure on android-amd64-emu in TestDebugCallGrowStack (https://build.golang.org/log/ee79c59d8a212e1461c433e52ff9427e44c2fad5):

##### GOMAXPROCS=2 runtime -cpu=1,2,4 -quick
--- FAIL: TestDebugCallGrowStack (0.00s)
    debug_test.go:183: executing on Go runtime stack
FAIL
exitcode=1FAIL	runtime	26.259s

[bcmills]

android-amd64-emu again: https://storage.googleapis.com/go-build-log/d068bbe4/android-amd64-emu_34b91ac9.log

[mvdan]

Perhaps related? #33944

[bcmills]

android-amd64-emu again: https://build.golang.org/log/96ce0d1b4decbb7edcdb2fc9e25da255d50638bb

[bcmills]

android-amd64-emu again:
https://storage.googleapis.com/go-build-log/a75e00b3/android-amd64-emu_b51c7469.log

CC @aclements @cherrymui @danscales @mknyszek

[gopherbot]

Change https://golang.org/cl/205248 mentions this issue: runtime: sleep a bit when waiting for running debug call goroutine

[bcmills]

android-amd64-emu again: https://storage.googleapis.com/go-build-log/af0f6d56/android-amd64-emu_efb37c55.log

[gopherbot]

Change https://golang.org/cl/206138 mentions this issue: runtime: skip TestDebugCall* on android-amd64-emu builder

[bcmills]

Still flaky:
https://build.golang.org/log/ba8d32ad60909355a4990a6a8f232695c42a7bc7

--- FAIL: TestDebugCallPanic (0.01s)
    debug_test.go:244: call from within the Go runtime
FAIL
exitcode=1FAIL	runtime	22.775s

[ianlancetaylor]

That's a different, albeit related, problem. Will send a CL.

[gopherbot]

Change https://golang.org/cl/207620 mentions this issue: runtime: treat call from runtime as transient in TestDebugCall