RFR: 8284813: x86 Code cleanup related to move instructions. [v2]

[Jatin Bhateja]

> Summary of changes:
> 
> - Correct feature checks in some assembler move instruction.
> - Explicitly pass opmask register in routines accepting merge argument.
> - Code re-organization related to move instruction, pull out the merge argument up to instruction pattern or top level caller.
> - Add missing encoding based move elision checks in some macro assembly routines.
> 
> Kindly review and share your feedback.
> 
> Regards,
> Jatin

Jatin Bhateja has updated the pull request with a new target base due to a merge or a rebase. The incremental webrev excludes the unrelated changes brought in by the merge/rebase. The pull request contains two additional commits since the last revision:

 - Merge branch 'master' of http://github.com/openjdk/jdk into JDK-8284813
 - 8284813: x86 Code cleanup related to move instructions.

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

Changes:
  - all: https://git.openjdk.java.net/jdk/pull/8230/files
  - new: https://git.openjdk.java.net/jdk/pull/8230/files/361c0d06..0792195e

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jdk&pr=8230&range=01
 - incr: https://webrevs.openjdk.java.net/?repo=jdk&pr=8230&range=00-01

  Stats: 37265 lines in 1482 files changed: 26857 ins; 4399 del; 6009 mod
  Patch: https://git.openjdk.java.net/jdk/pull/8230.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/8230/head:pull/8230

PR: https://git.openjdk.java.net/jdk/pull/8230