[LT] Support diagonal op (#75230)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/75230
Op diagonal is a view op which we can't code-gen yet. Therefore, support
it by making hand-written IR construction and lowering.
Test Plan: ./build/bin/test_lazy --gtest_filter=LazyOpsTest.TestDiagonal*
Reviewed By: wconstab
Differential Revision: D35378316
Pulled By: alanwaketan
fbshipit-source-id: 7958d00107aef20ac37aabcf2868346240977530
(cherry picked from commit 84155528fce484627c9688cfd92fd4aeb68219e5)
