RFR: Loom support for RedefineClasses [v2]

[Coleen Phillimore]

> Use _marking_cycle to determine whether a Method* is on the heap.
> This patch includes the patches for https://github.com/openjdk/jdk/pull/3852 and https://git.openjdk.java.net/jdk/pull/3861 which are going to be pushed to mainline.

Coleen Phillimore has updated the pull request incrementally with two additional commits since the last revision:

 - Remove RedefineTest from ProblemList.
 - Fix conditional for marking Method

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Changes:
  - all: https://git.openjdk.java.net/loom/pull/38/files
  - new: https://git.openjdk.java.net/loom/pull/38/files/872c733b..57e956ec

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=loom&pr=38&range=01
 - incr: https://webrevs.openjdk.java.net/?repo=loom&pr=38&range=00-01

  Stats: 10 lines in 2 files changed: 3 ins; 3 del; 4 mod
  Patch: https://git.openjdk.java.net/loom/pull/38.diff
  Fetch: git fetch https://git.openjdk.java.net/loom pull/38/head:pull/38

PR: https://git.openjdk.java.net/loom/pull/38