[code-reflection] RFR: Exception regions fix

[Adam Sotona]

BytecodeGenerator::computeExceptionRegionMembership now collects all necessary info into BitSets and directly declares the regions with CodeBuilder.
All tests are now passing.

Please review.

Thanks,
Adam

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Commit messages:
 - typo fix
 - fixed exception regions calculation in BytecodeGenerator

Changes: https://git.openjdk.org/babylon/pull/12/files
 Webrev: https://webrevs.openjdk.org/?repo=babylon&pr=12&range=00
  Stats: 110 lines in 3 files changed: 33 ins; 48 del; 29 mod
  Patch: https://git.openjdk.org/babylon/pull/12.diff
  Fetch: git fetch https://git.openjdk.org/babylon.git pull/12/head:pull/12

PR: https://git.openjdk.org/babylon/pull/12