RFR: 8255886: Shenandoah: Avoid register clash when calling LRB-runtime from interpreter [v3]

[Roman Kennke]

> JDK-8255762 caused test failure on Windows because of overlapping argument registers in the LRB runtime call. The problem is more general, though, but hasn't manifested anywhere else.
> 
> Testing: hotspot_gc_shenandoah (linux: x86_64, x86_32, windows: x86_64)

Roman Kennke 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 three additional commits since the last revision:

 - Merge branch 'master' into JDK-8255886
 - Generate regular call_VM_leaf for non-weak LRB
 - 8255886: Shenandoah: Avoid register clash when calling LRB-runtime from interpreter

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

Changes:
  - all: https://git.openjdk.java.net/jdk/pull/1054/files
  - new: https://git.openjdk.java.net/jdk/pull/1054/files/339dde59..504e56ae

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jdk&pr=1054&range=02
 - incr: https://webrevs.openjdk.java.net/?repo=jdk&pr=1054&range=01-02

  Stats: 10 lines in 3 files changed: 1 ins; 0 del; 9 mod
  Patch: https://git.openjdk.java.net/jdk/pull/1054.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/1054/head:pull/1054

PR: https://git.openjdk.java.net/jdk/pull/1054