runtime: flaky TestSegv on ppc64le

[gopherbot]

#!watchflakes
post <- goarch == "ppc64le" && pkg == "runtime" && test == "TestSegv"

Bug automatically created to track these flakes.

— watchflakes

[gopherbot]

Found new matching flaky dashboard failures for:

#!watchflakes
post <- pkg == "runtime" && test == "TestSegv"

2022-08-10 17:59 linux-ppc64le-power9osu go@9f8685f4 runtime.TestSegv (log)

--- FAIL: TestSegv (0.00s)
    --- FAIL: TestSegv/Segv (0.02s)
        testenv.go:473: [/workdir/tmp/go-build528637846/testprogcgo.exe Segv] exit status: exit status 2
        crash_cgo_test.go:611: SIGSEGV: segmentation violation
            PC=0x7c9399b43a14 m=3 sigcode=0

            r0   0xae	r1   0x7c9369abe0d0
            r2   0x7c9399b77f00	r3   0x0
            r4   0x7c9369abe200	r5   0x0
            r6   0x8	r7   0x0
            r8   0x7c937126f588	r9   0x0
            r10  0x0	r11  0x0
            r12  0x0	r13  0x7c9369ac68d0
            r14  0x0	r15  0x7c9371270b30
            r16  0x1a0	r17  0xc0000821a0
            r18  0x178	r19  0x1fffff
            r20  0x0	r21  0xc000080000
            r22  0x7c93692bed88	r23  0x3000
            r24  0x38	r25  0xffffffff80000000
            r26  0x0	r27  0x0
            r28  0x1006b6ec	r29  0x2
            r30  0x0	r31  0x0
            pc   0x7c9399b43a14	ctr  0x0
            link 0x101148b8	xer  0x0
            ccr  0x44424482	trap 0xc00

        crash_cgo_test.go:638: unexpectedly saw "runtime: " in output

2022-09-08 21:16 linux-ppc64le-buildlet go@a9a39822 runtime.TestSegv (log)

--- FAIL: TestSegv (0.00s)
    --- FAIL: TestSegv/Segv (0.03s)
        testenv.go:468: [/workdir/tmp/go-build2014546259/testprogcgo.exe Segv] exit status: exit status 2
        crash_cgo_test.go:611: SIGSEGV: segmentation violation
            PC=0x750cd6973a14 m=6 sigcode=0

            r0   0xae	r1   0x750cad17e0c0
            r2   0x750cd69a7f00	r3   0x0
            r4   0x750cad17e1f0	r5   0x0
            r6   0x8	r7   0x0
            r8   0x750c97fff588	r9   0x0
            r10  0x0	r11  0x0
            r12  0x0	r13  0x750cad1868d0
            r14  0x0	r15  0x750cad182d30
            r16  0x1a0	r17  0xc0001021a0
            r18  0x0	r19  0xc000102000
            r20  0x1	r21  0xc000100000
            r22  0x750cac97ed88	r23  0x750cad17e248
            r24  0x0	r25  0x1
            r26  0x0	r27  0x40
            r28  0xffffffffffffffff	r29  0x2
            r30  0x0	r31  0x0
            pc   0x750cd6973a14	ctr  0x0
            link 0x101164f8	xer  0x0
            ccr  0x24424482	trap 0xc00

        crash_cgo_test.go:638: unexpectedly saw "runtime: " in output

— watchflakes

[rsc]

These seem to be ppc64le-specific. Changed to track that.

[gopherbot]

Found new dashboard test flakes for:

#!watchflakes
post <- goarch == "ppc64le" && pkg == "runtime" && test == "TestSegv"

2022-09-21 15:30 linux-ppc64le-power9osu go@e246cf62 runtime.TestSegv (log)

--- FAIL: TestSegv (0.00s)
    --- FAIL: TestSegv/Segv (0.02s)
        testenv.go:468: [/workdir/tmp/go-build673890005/testprogcgo.exe Segv] exit status: exit status 2
        crash_cgo_test.go:617: SIGSEGV: segmentation violation
            PC=0x76f6671d3a14 m=4 sigcode=0

            r0   0xae	r1   0x76f63ea3e090
            r2   0x76f667207f00	r3   0x0
            r4   0x76f63ea3e1c0	r5   0x0
            r6   0x8	r7   0x0
            r8   0x76f63d18f588	r9   0x0
            r10  0x0	r11  0x0
            r12  0x0	r13  0x76f63ea468d0
            r14  0x0	r15  0x76f63d9e2d30
            r16  0x1a0	r17  0xc0001021a0
            r18  0x0	r19  0xc000102000
            r20  0x1	r21  0xc000100000
            r22  0x76f63e23ed88	r23  0x76f63ea3e218
            r24  0x0	r25  0x1
            r26  0x0	r27  0x38
            r28  0xffffffffffffffff	r29  0x2
            r30  0x0	r31  0x0
            pc   0x76f6671d3a14	ctr  0x0
            link 0x10116e78	xer  0x0
            ccr  0x24424482	trap 0xc00

        crash_cgo_test.go:648: unexpectedly saw "runtime: " in output

— watchflakes

[mknyszek]

This seems like a duplicate of #52963.