[code-reflection] RFR: Bytecode round 12

[Adam Sotona]

- Added test for operand values dominance revealed a bug in the BytecodeLift.
- Fixed BytecodeLift revealed regression in the roundtrip stability.
- Roundtrip instability was caused by a bug in the LocalsTypeMapper.

All the above is fixed and the roundtrip stability is restored.

Please review.

Thanks,
Adam

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Commit messages:
 - restored roundtrip stability - fixed LocalsTypeMapper
 - TestSmallCorpus actual numbers
 - Roundtrip stabilization - deferred redundant var initializations with defaults in BytecodeGenerator
 - fixed lifting of variables without dominant initial store
 - Added Op operand values declaration dominance verification to TestSmallCorpus

Changes: https://git.openjdk.org/babylon/pull/219/files
  Webrev: https://webrevs.openjdk.org/?repo=babylon&pr=219&range=00
  Stats: 162 lines in 4 files changed: 141 ins; 0 del; 21 mod
  Patch: https://git.openjdk.org/babylon/pull/219.diff
  Fetch: git fetch https://git.openjdk.org/babylon.git pull/219/head:pull/219

PR: https://git.openjdk.org/babylon/pull/219