Improve CHECK_OP macro (#29539)
Summary:
- Show values in question like glog.
- Handle expressions with logical operators properly by adding
parentheses around expressions.
- Allow outputting nullptr (some build failed without this)
Pull Request resolved: https://github.com/pytorch/pytorch/pull/29539
Reviewed By: dreiss
Differential Revision: D19698991
Pulled By: ljk53
fbshipit-source-id: e329c01622cfc386ac009904092519a4adfe94a8
