RFR: 8288294: [vector] Add Identity/Ideal transformations for vector logic operations

[Xiaohong Gong]

This patch adds the following transformations for vector logic operations such as "`AndV, OrV, XorV`", incuding:

  (AndV v (Replicate m1))   => v
  (AndV v (Replicate zero)) => Replicate zero
  (AndV v v)                => v

  (OrV v (Replicate m1))    => Replicate m1
  (OrV v (Replicate zero))  => v
  (OrV v v)                 => v

  (XorV v v)                => Replicate zero

where "`m1`" is the integer constant -1, together with the same optimizations for vector mask operations like "`AndVMask, OrVMask, XorVMask`".

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Commit messages:
 - 8288294: [vector] Add Identity/Ideal transformations for vector logic operations

Changes: https://git.openjdk.org/jdk/pull/9211/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=9211&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8288294
  Stats: 640 lines in 4 files changed: 630 ins; 0 del; 10 mod
  Patch: https://git.openjdk.org/jdk/pull/9211.diff
  Fetch: git fetch https://git.openjdk.org/jdk pull/9211/head:pull/9211

PR: https://git.openjdk.org/jdk/pull/9211