[code-reflection] RFR: Fix SSABraun bug and add SSA tests [v2]

[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 five additional commits since the last revision:

 - 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

-------------

Changes:
  - all: https://git.openjdk.org/babylon/pull/542/files
  - new: https://git.openjdk.org/babylon/pull/542/files/380d75c6..e3ba9dd6

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=babylon&pr=542&range=01
 - incr: https://webrevs.openjdk.org/?repo=babylon&pr=542&range=00-01

  Stats: 4708 lines in 62 files changed: 1827 ins; 2312 del; 569 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