RFR: 8369167: C2: refactor LShiftINode/LShiftLNode Value/Identity/Ideal [v5]

[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 four additional commits since the last revision:

 - Update src/hotspot/share/opto/mulnode.cpp
   
   Co-authored-by: Emanuel Peter <emanuel.peter at oracle.com>
 - Update src/hotspot/share/opto/mulnode.cpp
   
   Co-authored-by: Emanuel Peter <emanuel.peter at oracle.com>
 - Update src/hotspot/share/opto/mulnode.cpp
   
   Co-authored-by: Emanuel Peter <emanuel.peter at oracle.com>
 - Update src/hotspot/share/opto/mulnode.cpp
   
   Co-authored-by: Emanuel Peter <emanuel.peter at oracle.com>

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/27725/files
  - new: https://git.openjdk.org/jdk/pull/27725/files/040d8541..6865e1c4

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=27725&range=04
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=27725&range=03-04

  Stats: 4 lines in 1 file changed: 0 ins; 0 del; 4 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