[code-reflection] RFR: Onnx loop op work continuation + WalkTheMazeTest

[Adam Sotona]

Onnx loop op work continuation + WalkTheMazeTest

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Commit messages:
 - WalkTheMazeTest
 - Flow control test implementation - work in progress
 - added support for static initializer fields
 - recurent inlining and deduplication of initializers
 - If elseBody and thenBody swap
 - SimpleTest cleanup
 - Loop op work in progress
 - Loop op work in progress

Changes: https://git.openjdk.org/babylon/pull/367/files
  Webrev: https://webrevs.openjdk.org/?repo=babylon&pr=367&range=00
  Stats: 491 lines in 8 files changed: 368 ins; 23 del; 100 mod
  Patch: https://git.openjdk.org/babylon/pull/367.diff
  Fetch: git fetch https://git.openjdk.org/babylon.git pull/367/head:pull/367

PR: https://git.openjdk.org/babylon/pull/367