RFR: 8284813: x86 Code cleanup related to move instructions. [v3]

[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 incrementally with one additional commit since the last revision:

  8284813: Review comments resolutions.

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

Changes:
  - all: https://git.openjdk.java.net/jdk/pull/8230/files
  - new: https://git.openjdk.java.net/jdk/pull/8230/files/0792195e..939c0317

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jdk&pr=8230&range=02
 - incr: https://webrevs.openjdk.java.net/?repo=jdk&pr=8230&range=01-02

  Stats: 3 lines in 1 file changed: 0 ins; 0 del; 3 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