[code-reflection] RFR: Fix SSABraun bug and add SSA tests [v3]

[Ruby Chen]

> Fix a bug in SSABraun where, in `tryRemoveTrivialPhi()`, a phi stored in `same` that is later deleted in a recursive `tryRemoveTrivialPhi()` call is still returned despite being deleted. 
> 
> Add five tests to TestSSA: `deadCode(), ifelseLoopNested(), violaJones(), binarySearch(),` and `quicksort()`. `violaJones()` is inspired by the method `findFeaturesKernel` in HAT kernel ViolaJones, which is the bug first presented itself.

Ruby Chen has updated the pull request incrementally with one additional commit since the last revision:

  Add one more test and change equals

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Changes:
  - all: https://git.openjdk.org/babylon/pull/542/files
  - new: https://git.openjdk.org/babylon/pull/542/files/e3ba9dd6..a2a723e5

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=babylon&pr=542&range=02
 - incr: https://webrevs.openjdk.org/?repo=babylon&pr=542&range=01-02

  Stats: 24 lines in 2 files changed: 23 ins; 0 del; 1 mod
  Patch: https://git.openjdk.org/babylon/pull/542.diff
  Fetch: git fetch https://git.openjdk.org/babylon.git pull/542/head:pull/542

PR: https://git.openjdk.org/babylon/pull/542