build: add rule to clean addon tests build

[joyeecheung]

Add a rule to the makefile to clean up files generated during testing addons.

Note: when switching from a newer branch, where the addon tests have been built, to an older branch that don't have some of the addon tests, there would be leftover build directories in those test folders.

$ ls test/addons/node-module-version/
binding.cc  binding.gyp build test.js
$ git checkout v4.8.0
$ ls test/addons/node-module-version/
build

test/addons/.buildstamp would try to use node-gyp to build them, only to find the binding.gyp missing. If we run this rule before switching branches, there won't be leftover build and those test folders would not be kept when the branches are switched. I think the test/addons/.buildstamp can have some kind of conditions to avoid that or just delete folders with only build, but not sure what's the appropriate way to do this.

Checklist

• make -j4 test (UNIX), or vcbuild test (Windows) passes
• commit message follows commit guidelines

Affected core subsystem(s)

build

[Fishrock123]

yes please

[bnoordhuis]

LGTM. FWIW, there's another add-on in test/gc.

[Trott]

Should the same functionality be added to vcbuild.bat so Windows folks have it too?

[MylesBorins]

a++ Great work

LGTM

[joyeecheung]

@bnoordhuis Oh yes, though I think that one should be test-gc-clean (corresponds to test-gc), it would be a bit weird if the rules are not symmetrical.

@Trott +1 on the idea of adding this to vcbuild.bat, though I know so little about how to write one and I don't have Windows at the moment (technically one doesn't need Windows to consume it, but still), so I think better leave to another PR if anyone want to do it :)

[joyeecheung]

Hmm...I've tried to do a test-gc-clean but then I think it would be even better if we just have a test-clean that depends on all these tests-cleaning rules and clean them all :D. I think I can get this one in first, meanwhile try to figure out what other test-* rules can be cleaned and make another PR for test-clean and its "parents".

[joyeecheung]

CI: https://ci.nodejs.org/job/node-test-pull-request/6587/

[joyeecheung]

ARM failure is not a failure, as usual..

Landed in 813b312, thanks!

[jasnell]

Landed in in v6.x-staging. If it should land in v4.x-staging, please open a backport PR

[joyeecheung]

Depends on #10856