test-child-process-uid-gid fails on FreeBSD

[UnitedMarsupials-zz]

Performing "make test" on the freshly-built node-7.4.0 I see the following:

=== release test-child-process-uid-gid ===                                     
Path: parallel/test-child-process-uid-gid
assert.js:85
  throw new assert.AssertionError({
  ^
AssertionError: Missing expected exception..
    at _throws (assert.js:339:5)
    at Function.throws (assert.js:363:3)
    at Object.<anonymous> (/spare/usr/ports/www/node/work/node-v7.4.0/test/parallel/test-child-process-uid-gid.js:17:8)
    at Module._compile (module.js:571:32)
    at Object.Module._extensions..js (module.js:580:10)
    at Module.load (module.js:488:32)
    at tryModuleLoad (module.js:447:12)
    at Function.Module._load (module.js:439:3)
    at Module.runMain (module.js:605:10)
    at run (bootstrap_node.js:420:7)
Command: out/Release/node /spare/usr/ports/www/node/work/node-v7.4.0/test/parallel/test-child-process-uid-gid.js
[01:30|%  92|+ 1216|-   1]: release testerSyncFolderItemsRequest.onSendError aMsg:Error during connecting to hostname 'mail.humedica.com'. Is the host down?. (STATUS_CONNECTING_TO)
[02:11|% 100|+ 1319|-   1]: Done                                               
gmake[1]: *** [Makefile:126: test] Error 1
gmake[1]: Leaving directory '/spare/usr/ports/www/node/work/node-v7.4.0'
*** Error code 1

I am running the test as myself (not as root)... The failing snippet is:

assert.throws(() => {
  spawn('echo', ['fhqwhgads'], {gid: 0});
}, expectedError);

It fails, because my account belongs to group 0 (wheel). In fact, it is my only group. The test should be checking for such situations similarly to how it already checks for being run by uid 0.

[UnitedMarsupials-zz]

I'm afraid, the committed fix is not sufficient. The effective GID may be different from 0, but, if the user's account belongs to group 0 as well, the spawn may still succeed. So, the check may need to go through all of the account's groups to make sure, none of them is 0. Frankly, I don't think, it is worth the trouble -- I'd advise to simply remove the second test from this file.

Also, this is not a FreeBSD-specific problem, so I don't think, the "freebsd" tag is appropriate.

[cjihrig]

I don't think we should remove the check. It's the only test for that option that we have, save a type checking test. I updated the test in #10647 to check for all groups.