RFR: 8369167: C2: refactor LShiftINode/LShiftLNode Value/Identity/Ideal [v3]

[Roland Westrelin]

> This change refactor code that's similar for LShiftINode and
> LShiftLNode into shared methods. I also added extra test cases to
> cover all transformations.

Roland Westrelin has updated the pull request incrementally with one additional commit since the last revision:

  review

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Changes:
  - all: https://git.openjdk.org/jdk/pull/27725/files
  - new: https://git.openjdk.org/jdk/pull/27725/files/05ff54dc..e521d918

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=27725&range=02
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=27725&range=01-02

  Stats: 16 lines in 2 files changed: 0 ins; 0 del; 16 mod
  Patch: https://git.openjdk.org/jdk/pull/27725.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/27725/head:pull/27725

PR: https://git.openjdk.org/jdk/pull/27725