check_nan bug fix and skip bind for struct params (issue204077)
Reviewers: dev-osl_imageworks.com, osl-dev_googlegroups.com,
Two small things I noticed while debugging something unrelated.
1) check_nan was off-by one
2) we allocate space for struct params even though they are never used
I also added a bit more information to the check_nan output (including
which point was nan).
Please review this at http://codereview.appspot.com/204077/show