cmd/go: TestBuildIDContainsArchModeEnv/386 fails on linux/386 in Go 1.14 and 1.13, not 1.15 [1.14 backport]

[gopherbot]

@dmitshur requested issue #39544 to be considered for backport to the next 1.14 minor release.

@gopherbot Please backport to the last 2 releases. This is a test fix. It makes a cmd/go test less strict and enables it to pass in all environments, which matches the behavior of the same test in the latest version, which has been confirmed to be most optimal.

[gopherbot]

Change https://golang.org/cl/239738 mentions this issue: [release-branch.go1.14] cmd/go: convert TestBuildIDContainsArchModeEnv to the script framework

[cagedmantis]

This is a serious issue with no workaround which impacts the release process. Approved.

[gopherbot]

Closed by merging efed90a to release-branch.go1.14.