RFR: 8265956: JVM crashes when matching LShiftVB Node [v6]

[Wang Huang]

> It is fount that the rule `match(Set dst (LShiftVB src shift))` is missing on many cpus, such like `aarch64` and `x86`. It is this reason that JVM will crash under `JDK-8265956`'s test case. In this commit, I :
> * show the crash case `TestVectorShuffleIotaShort`
> * ~~solve the issue on `aarch64` and `x86` by adding the rule.~~  solve the issue by adding `LShiftCntVNode` without adding any rule
> * test after fixing on tire1~3
> 
> Thank you for your review. Any suggestion is welcome. 
>                          Wang Huang

Wang Huang has updated the pull request incrementally with one additional commit since the last revision:

  fix test case problem

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

Changes:
  - all: https://git.openjdk.java.net/jdk/pull/3747/files
  - new: https://git.openjdk.java.net/jdk/pull/3747/files/bda9c29f..6dbb458d

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jdk&pr=3747&range=05
 - incr: https://webrevs.openjdk.java.net/?repo=jdk&pr=3747&range=04-05

  Stats: 33 lines in 1 file changed: 21 ins; 5 del; 7 mod
  Patch: https://git.openjdk.java.net/jdk/pull/3747.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/3747/head:pull/3747

PR: https://git.openjdk.java.net/jdk/pull/3747