runtime: TestDebugCallGrowStack failures

[gopherbot]

#!watchflakes
post <- pkg == "runtime" && test == "TestDebugCallGrowStack" && log ~ `morestack on g0`

Issue created automatically to collect these failures.

Example (log):

fatal: morestack on g0
trap in unknown function runtime.abort
SIGTRAP: trace trap
PC=0x70a99c42f662 m=12 sigcode=128

rax    0x17
rbx    0x70a99c767be2
rcx    0x70a99c430fd5
rdx    0x17
rdi    0x2
...
fs     0x0
gs     0x0

runtime.notetsleepg(0x70a900000064?, 0x30?)
	/workdir/go/src/runtime/lock_futex.go:236 +0x29 fp=0xc00091be78 sp=0xc00091be40 pc=0x70a99c3c37e9
runtime.InjectDebugCall(0xc0000c3040, {0x70a99c82d7c0, 0x70a99c8c2cb8}, 0x0, {0x0, 0x0}, 0x70a99c8c31e0, 0x0)
	/workdir/go/src/runtime/export_debug_test.go:68 +0x3c5 fp=0xc00091bf00 sp=0xc00091be78 pc=0x70a99c4200c5
runtime_test.TestDebugCallGrowStack(0xc000304340)
	/workdir/go/src/runtime/debug_test.go:221 +0x56 fp=0xc00091bf70 sp=0xc00091bf00 pc=0x70a99c6b0a76
testing.tRunner(0xc000304340, 0x70a99c8c15c0)

— watchflakes

[gopherbot]

Found new dashboard test flakes for:

#!watchflakes
default <- pkg == "runtime" && test == "TestDebugCallGrowStack"

2023-10-03 14:10 android-amd64-emu go@98289021 runtime.TestDebugCallGrowStack (log)

fatal: morestack on g0
trap in unknown function runtime.abort
SIGTRAP: trace trap
PC=0x70a99c42f662 m=12 sigcode=128

rax    0x17
rbx    0x70a99c767be2
rcx    0x70a99c430fd5
rdx    0x17
rdi    0x2
...
fs     0x0
gs     0x0

runtime.notetsleepg(0x70a900000064?, 0x30?)
	/workdir/go/src/runtime/lock_futex.go:236 +0x29 fp=0xc00091be78 sp=0xc00091be40 pc=0x70a99c3c37e9
runtime.InjectDebugCall(0xc0000c3040, {0x70a99c82d7c0, 0x70a99c8c2cb8}, 0x0, {0x0, 0x0}, 0x70a99c8c31e0, 0x0)
	/workdir/go/src/runtime/export_debug_test.go:68 +0x3c5 fp=0xc00091bf00 sp=0xc00091be78 pc=0x70a99c4200c5
runtime_test.TestDebugCallGrowStack(0xc000304340)
	/workdir/go/src/runtime/debug_test.go:221 +0x56 fp=0xc00091bf70 sp=0xc00091bf00 pc=0x70a99c6b0a76
testing.tRunner(0xc000304340, 0x70a99c8c15c0)

— watchflakes

[bcmills]

Compare #53250, #51001.

[bcmills]

Updated the watchflakes pattern to use post instead of default and match on the failure message.