Optimize is_symbolic test and some refactor (#86230)
Our SymInt rep can be represented more efficiently as just a greater than test, but the compiler doesn't seem to figure it out. Help it out.
There is also some refactoring to simplify the code and add more debugging.
Signed-off-by: Edward Z. Yang <ezyang@fb.com>
Pull Request resolved: https://github.com/pytorch/pytorch/pull/86230
Approved by: https://github.com/albanD
