windows-amd64 tests flaky: TestGcPacer, TestCgoPanicCallback, TestBigStackCallbackCgo, ...

[dagood]

https://dev.azure.com/dnceng/internal/_build/results?buildId=1451609&view=logs&j=5a2439d3-40cd-5cda-520e-11af88128fb3&s=96ac2280-8cb4-5df5-99de-dd2da759617d&t=a1b03d73-1679-5340-7eef-275cc3387d35&l=389

=== Failed
=== FAIL: runtime TestCallbackInAnotherThread (0.14s)
=== FAIL: runtime TestCgoPanicCallback (unknown)
=== FAIL: runtime TestBigStackCallbackCgo (unknown)
=== FAIL: runtime TestGcPacer/Steady (unknown)
=== FAIL: runtime TestCheckPtr/CheckPtrAlignmentNoPtr (unknown)
=== FAIL: runtime TestGcPacer/OscAlloc (unknown)
=== FAIL: runtime TestNetpollDeadlock (unknown)
=== FAIL: runtime TestCheckPtr (unknown)
=== FAIL: runtime TestGcPacer/StepScannableFrac (unknown)
=== FAIL: runtime TestRecoverBeforePanicAfterGoexit (unknown)
=== FAIL: runtime TestGcPacer (unknown)
=== FAIL: runtime TestCheckPtr/CheckPtrSliceFail (unknown)
=== FAIL: runtime TestCheckPtr2 (unknown)
=== FAIL: runtime TestCheckPtr/CheckPtrArithmetic2 (unknown)
=== FAIL: runtime TestCheckPtr/CheckPtrSmall (unknown)
=== FAIL: runtime TestRecoverBeforePanicAfterGoexit2 (unknown)
=== FAIL: runtime TestCheckPtr/CheckPtrAlignmentPtr (unknown)
=== FAIL: runtime TestCheckPtr/CheckPtrAlignmentNilPtr (unknown)
=== FAIL: runtime TestCheckPtr/CheckPtrSliceOK (unknown)
=== FAIL: runtime TestGcPacer/JitterAlloc (unknown)
=== FAIL: runtime TestVDSO (unknown)
=== FAIL: runtime TestGcPacer/StepAlloc (unknown)
=== FAIL: runtime TestGcPacer/HeavyJitterAlloc (unknown)
=== FAIL: runtime TestCheckPtr/CheckPtrArithmetic (unknown)
=== FAIL: runtime TestGcPacer/HeavyStepAlloc (unknown)
=== FAIL: runtime TestPanicTraceback (unknown)
=== FAIL: runtime TestCheckPtr/CheckPtrSize (unknown)

I'm not sure if there's a common thread connecting these tests. 😕

Some failures are shared with:

• windows-amd64 tests flaky (cgo and others) #251