RFR: 8292761: x86: Clone nodes to match complex rules [v2]

[Quan Anh Mai]

> Hi,
> 
> This patch tries to clone a node if it can be matched as a part of a BMI and lea pattern. This may reduce the live range of a local or remove that local completely.
> 
> Please take a look and have some reviews. Thanks a lot.

Quan Anh Mai 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 ten additional commits since the last revision:

 - Merge branch 'master' into cloneSimpleNodes
 - fix
 - Merge branch 'master' into cloneSimpleNodes
 - shorten
 - improve checks
 - lea patterns
 - refactor
 - lea patterns
 - first commit

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/9977/files
  - new: https://git.openjdk.org/jdk/pull/9977/files/ef8b3733..7df6ed7e

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=9977&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=9977&range=00-01

  Stats: 59562 lines in 1129 files changed: 28624 ins; 25673 del; 5265 mod
  Patch: https://git.openjdk.org/jdk/pull/9977.diff
  Fetch: git fetch https://git.openjdk.org/jdk pull/9977/head:pull/9977

PR: https://git.openjdk.org/jdk/pull/9977