Fix ruby segment fault (#3708)

* Fix ruby segment fault

1) rb_ary_new cannot be called during allocate function. During allocate
fucntion, the containing object hasn't been marked and rb_ary_new may
invoke gc to collect containing object.
2) The global map should be marked before allocating it. Otherwise it
may be garbage collected.

* Add test

* Remove commented code

* Fix grammer error

1 files changed, 5 insertions, 0 deletions

diff --git a/.gitignore b/.gitignore
index fdc52bf7..d5196041 100644
--- a/.gitignore
+++ b/.gitignore
@@ -171,3 +171,8 @@ js/testproto_libs2.js
 
 # Ignore the bazel symlinks
 /bazel-*
+
+# ruby test output
+ruby/lib/
+ruby/tests/generated_code_pb.rb
+ruby/tests/test_import_pb.rb