[sledge] Use Theory.oriented_equality for arg of Subst.compose1
[sledge] Use Theory.oriented_equality for arg of Subst.compose1

Summary:
The `Theory.oriented_equality` type is more informative than the
generic `key` and `data` labeled arguments.

Differential Revision: D34378624

fbshipit-source-id: 29d4e356ad

facebook/infer,facebook/infer,facebook/infer,facebook/infer,facebook/infer,facebook/infer,facebook/infer