RFR: 8288445: AArch64: C2 compilation fails with guarantee(!true || (true && (shift != 0))) failed: impossible encoding [v4]

[Dean Long]

> The range for aarch64 vector right-shift is 1 to the element width.  This issue fixes the problem in the back-end.  There is a separate problem in the front-end that shift by 0 is not always optimized out.

Dean Long has updated the pull request incrementally with two additional commits since the last revision:

 - fix comment
 - Update test/hotspot/jtreg/compiler/codegen/ShiftByZero.java
   
   Co-authored-by: Andrew Haley <aph-open at littlepinkcloud.com>

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

Changes:
  - all: https://git.openjdk.org/jdk19/pull/40/files
  - new: https://git.openjdk.org/jdk19/pull/40/files/0f927ce7..583c54c0

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk19&pr=40&range=03
 - incr: https://webrevs.openjdk.org/?repo=jdk19&pr=40&range=02-03

  Stats: 2 lines in 1 file changed: 2 ins; 0 del; 0 mod
  Patch: https://git.openjdk.org/jdk19/pull/40.diff
  Fetch: git fetch https://git.openjdk.org/jdk19 pull/40/head:pull/40

PR: https://git.openjdk.org/jdk19/pull/40