RFR: 8265907: JVM crashes when matching VectorMaskCmp Node [v6]

[Wang Huang]

> * fix the issue JDK-8265907
> * all archs might be effected by this bug. I fixed x86 and aarch64.

Wang Huang has updated the pull request with a new target base due to a merge or a rebase. The pull request now contains five commits:

 - Merge master
 - fix x86's problem in other way
 - Merge branch 'master' into JDK-8265907
 - fix x86's bug
 - 8265907: JVM crashes when matching VectorMaskCmp Node

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Changes: https://git.openjdk.java.net/jdk/pull/3670/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=3670&range=05
  Stats: 78 lines in 5 files changed: 73 ins; 3 del; 2 mod
  Patch: https://git.openjdk.java.net/jdk/pull/3670.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/3670/head:pull/3670

PR: https://git.openjdk.java.net/jdk/pull/3670