[Functionalization] Fix test_simple_expand
Summary:
This pull request fixes TestDynamicShapes.test_simple_expand by:
1. enabling python dispatcher in the test such that dynamic ops are decomposed correctly,
2. implementing missing sym size ops, ge and clone.
Test Plan:
XLA_EXPERIMENTAL="nonzero:masked_select:masked_scatter" python test/test_dynamic_shapes.py -v TestDynamicShapes.test_simple_expand
