RFR: 8278784: C2: Refactor PhaseIdealLoop::remix_address_expressions() so it operates on longs [v3]

[Roland Westrelin]

> The logic in PhaseIdealLoop::remix_address_expressions() that's
> specific to int nodes apply equally to long nodes. This change
> refactors that code so it applies to both integer types. This improves
> performance on some of panama's micro-benchmarks.

Roland Westrelin has updated the pull request incrementally with one additional commit since the last revision:

  Christian's review

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

Changes:
  - all: https://git.openjdk.java.net/jdk/pull/6892/files
  - new: https://git.openjdk.java.net/jdk/pull/6892/files/06f67b56..e8e3385b

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jdk&pr=6892&range=02
 - incr: https://webrevs.openjdk.java.net/?repo=jdk&pr=6892&range=01-02

  Stats: 1 line in 1 file changed: 0 ins; 1 del; 0 mod
  Patch: https://git.openjdk.java.net/jdk/pull/6892.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/6892/head:pull/6892

PR: https://git.openjdk.java.net/jdk/pull/6892