Add utility functions for reference counting.

Bug 26851951

Change-Id: I5494d61927eb4c1faff320aa7cd6cebe81800f29
Reviewed-on: https://swiftshader-review.googlesource.com/4712
Tested-by: Nicolas Capens <capn@google.com>
Reviewed-by: Alexis Hétu <sugoi@google.com>
Reviewed-by: Nicolas Capens <capn@google.com>
7 files changed