Add pattern to detect for loop indexing into tensor (#81056)
Differential Revision: [D37725266](https://our.internmc.facebook.com/intern/diff/D37725266)
Summary: This commit added a pattern in the pattern matcher to detect if for loop & indexing is used that can be vectorized.
Test Plan: Added a test in test_profiler.py that creates a bootstrap example.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/81056
Approved by: https://github.com/robieta
