x/tools/cmd/guru: TestIssue17515 failing on x_tools-gotip-wasip1-wasm_wasmtime due to symlink permission error

[bcmills]

Go version

N/A

What operating system and processor architecture are you using (go env)?

N/A

What did you do?

Check LUCI build status at https://ci.chromium.org/p/golang/g/x-tools-gotip/console.

What did you expect to see?

All tests passing.

What did you see instead?

https://ci.chromium.org/ui/p/golang/builders/ci/x_tools-gotip-wasip1-wasm_wasmtime/b8761809133576738257/test-results:

=== RUN   TestIssue17515
    unit_test.go:56: symlink /tmp/home2806657382/go/src /tmp/home2806657382/src: Operation not permitted
--- FAIL: TestIssue17515 (0.00s)

This test attempts to guard the os.Symlink call based on GOOS, but it uses a negative list instead of a positive one, so erroneously assumes that new or unrecognized GOOS values support symlinks:
https://cs.opensource.google/go/x/tools/+/master:cmd/guru/unit_test.go;drc=559c4300daa4efe55422df9bba86d125cdf1d9ef;l=57

[gopherbot]

Change https://go.dev/cl/549555 mentions this issue: cmd/guru,internal/robustio: make tests robust to os.Symlink errors