[code-reflection] RFR: Fix SSABraun bug and add SSA tests [v4]

[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 with a new target base due to a merge or a rebase. The incremental webrev excludes the unrelated changes brought in by the merge/rebase. The pull request contains seven additional commits since the last revision:

 - Merge branch 'openjdk:code-reflection' into inline
 - Add one more test and change equals
 - Replace deleted phi after recursive call
 - Merge branch 'openjdk:code-reflection' into inline
 - Merge branch 'openjdk:code-reflection' into inline
 - Merge branch 'openjdk:code-reflection' into inline
 - Fix SSABraun bug and add SSA tests

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Changes:
  - all: https://git.openjdk.org/babylon/pull/542/files
  - new: https://git.openjdk.org/babylon/pull/542/files/a2a723e5..0f1d75d6

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=babylon&pr=542&range=03
 - incr: https://webrevs.openjdk.org/?repo=babylon&pr=542&range=02-03

  Stats: 2998 lines in 36 files changed: 2738 ins; 76 del; 184 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