RFR: 8278036: Saving rscratch1 is optional in MacroAssembler::verify_heapbase [v2]

[Yi-Fan Tsai]

> 8278036: Saving rscratch1 is optional in MacroAssembler::verify_heapbase

Yi-Fan Tsai 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 four additional commits since the last revision:

 - Merge branch 'openjdk:master' into pushpop
 - Limit the change local
 - Merge branch 'openjdk:master' into pushpop
 - 8278036: Remove redundant push/pop in verify_heapbase

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

Changes:
  - all: https://git.openjdk.java.net/jdk/pull/7067/files
  - new: https://git.openjdk.java.net/jdk/pull/7067/files/258300d4..efabb85c

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jdk&pr=7067&range=01
 - incr: https://webrevs.openjdk.java.net/?repo=jdk&pr=7067&range=00-01

  Stats: 9100 lines in 370 files changed: 6194 ins; 1889 del; 1017 mod
  Patch: https://git.openjdk.java.net/jdk/pull/7067.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/7067/head:pull/7067

PR: https://git.openjdk.java.net/jdk/pull/7067