RFR: CODETOOLS-7903326: Refactor CharacterRangeTableAttribute

[Alexandre Iline]

This extracts generic part of *.instrument.asm.CharacterRangeTableAttribute class into a new class *.instrument.CharacterRangeTable

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

Commit messages:
 - A getter for CharacterRangeTableAttribute.crt
 - CODETOOLS-7903326: Refactor CharacterRangeTableAttribute

Changes: https://git.openjdk.org/jcov/pull/27/files
 Webrev: https://webrevs.openjdk.org/?repo=jcov&pr=27&range=00
  Issue: https://bugs.openjdk.org/browse/CODETOOLS-7903326
  Stats: 387 lines in 8 files changed: 199 ins; 151 del; 37 mod
  Patch: https://git.openjdk.org/jcov/pull/27.diff
  Fetch: git fetch https://git.openjdk.org/jcov pull/27/head:pull/27

PR: https://git.openjdk.org/jcov/pull/27