src: make AtExit callback's per Environment

This commit attempts to address one of the TODOs in
https://github.com/nodejs/node/issues/4641 regarding making the
AtExit callback's per environment, instead of the current global.

bnoordhuis provided a few options for solving this, and one was to
use a thread-local which is what this commit attempts to do.

PR-URL: https://github.com/nodejs/node/pull/9163
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: bnoordhuis - Ben Noordhuis <info@bnoordhuis.nl>

1 files changed, 1 insertions, 0 deletions

diff --git a/node.gyp b/node.gyp
index 1291398724..5f480001da 100644
--- a/node.gyp
+++ b/node.gyp
@@ -642,6 +642,7 @@
 
       'sources': [
         'test/cctest/test_base64.cc',
+        'test/cctest/test_environment.cc',
         'test/cctest/test_util.cc',
         'test/cctest/test_url.cc'
       ],