crypto/subtle: xor fails when run with race+purego [1.20 backport]

[gopherbot]

@randall77 requested issue #59334 to be considered for backport to the next 1.20 minor release.

@gopherbot please open a backport issue to 1.20. This is a potential crash when running with the race detector.

This code is quite different in 1.19. I don't think it suffers from the same issue.

[gopherbot]

Change https://go.dev/cl/481238 mentions this issue: [release-branch.go1.20] crypto/subtle: don't cast to *uintptr when word size is 0

[gopherbot]

Closed by merging dcc9bdf to release-branch.go1.20.