Refactor unit test
Refactor unit test

Summary: Check dominance of `instance-of` instructions instead of exact code, so that block linearization, register allocation etc do not matter.

Reviewed By: NTillmann

Differential Revision: D33368658

fbshipit-source-id: ef9f083b8a19aa2e73e31f1d0da443f2bfefaad8

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