testing: "Access is denied." when cleaning up TempDir on windows-amd64-2012

[bcmills]

greplogs --dashboard -md -l -e 'TempDir RemoveAll cleanup: CreateFile .*: Access is denied.'

2021-12-08T15:30:52-9fe77de/windows-amd64-2012

--- FAIL: TestRWithNonexistentFile (0.71s)
    testing.go:1091: TempDir RemoveAll cleanup: CreateFile C:\Users\gopher\AppData\Local\Temp\1\TestRWithNonexistentFile1327565502\001\pack.exe: Access is denied.
FAIL
FAIL	cmd/pack	4.162s

2021-10-27T21:37:54-749f6e9/windows-amd64-2012

--- FAIL: TestDefaultLinkerDWARF (1.25s)
    file_test.go:395: Testprog output:
        base=0x110000
        main=0x19d040
        offset=0x8d040
    file_test.go:442: Found main.main
    testing.go:1090: TempDir RemoveAll cleanup: CreateFile C:\Users\gopher\AppData\Local\Temp\1\TestDefaultLinkerDWARF1018842931\001\a.exe: Access is denied.
FAIL
FAIL	debug/pe	4.240s

2021-10-15T16:57:36-a80e53e/windows-amd64-2012

--- FAIL: TestExternalLinkerDWARF (1.24s)
    file_test.go:395: Testprog output:
        base=0x70000
        main=0xfcc60
        offset=0x8cc60
    file_test.go:442: Found main.main
    testing.go:1059: TempDir RemoveAll cleanup: CreateFile C:\Users\gopher\AppData\Local\Temp\1\TestExternalLinkerDWARF1567542787\001\a.exe: Access is denied.
FAIL
FAIL	debug/pe	4.089s

2021-06-16T16:38:43-a294e4e/windows-amd64-2012

--- FAIL: TestRWithNonexistentFile (0.73s)
    testing.go:950: TempDir RemoveAll cleanup: CreateFile C:\Users\gopher\AppData\Local\Temp\1\TestRWithNonexistentFile2669366332\001\pack.exe: Access is denied.
FAIL
FAIL	cmd/pack	3.283s

2021-06-08T20:39:45-cb80937/windows-amd64-2012

--- FAIL: TestDefaultLinkerDWARF (1.14s)
    file_test.go:395: Testprog output:
        base=0x1340000
        main=0x13cf740
        offset=0x8f740
    file_test.go:442: Found main.main
    testing.go:950: TempDir RemoveAll cleanup: CreateFile C:\Users\gopher\AppData\Local\Temp\1\TestDefaultLinkerDWARF1440061601\001\a.exe: Access is denied.
FAIL
FAIL	debug/pe	3.841s

2021-05-02T20:59:26-bb09f8a/windows-amd64-2012

--- FAIL: TestRWithNonexistentFile (0.71s)
    testing.go:950: TempDir RemoveAll cleanup: CreateFile C:\Users\gopher\AppData\Local\Temp\1\TestRWithNonexistentFile3706200250\001\pack.exe: Access is denied.
FAIL
FAIL	cmd/pack	3.532s

2021-04-30T00:08:50-02ab8d1/windows-amd64-2012

--- FAIL: TestRWithNonexistentFile (0.72s)
    testing.go:950: TempDir RemoveAll cleanup: CreateFile C:\Users\gopher\AppData\Local\Temp\1\TestRWithNonexistentFile883083571\001\pack.exe: Access is denied.
FAIL
FAIL	cmd/pack	3.707s

2021-04-21T13:27:17-381252f/windows-amd64-2012

--- FAIL: TestDefaultLinkerDWARF (1.25s)
    file_test.go:395: Testprog output:
        base=0x240000
        main=0x2cf440
        offset=0x8f440
    file_test.go:442: Found main.main
    testing.go:947: TempDir RemoveAll cleanup: CreateFile C:\Users\gopher\AppData\Local\Temp\1\TestDefaultLinkerDWARF1597920265\001\a.exe: Access is denied.
FAIL
FAIL	debug/pe	4.436s

[bcmills]

See previously #25965, #48012, #45672.

[bcmills]

The straightforward fix for these tests in particular is to make the testing package use essentially the same retry loop on Windows that cmd/go itself uses.

Marking as release-blocker (via #11811) because this is a recurring source of test failures on the dashboard. (I can mail a fix at some point in the next week or so.)

That won't fix #25965 in the general case, but it will at least fix the common-case failures that occur via testing.TempDir().

[gopherbot]

Change https://golang.org/cl/371296 mentions this issue: testing: retry spurious errors from RemoveAll for temp directories