RFR: 8291830: jvmti/RedefineClasses/StressRedefine failed: assert(!is_null(v)) failed: narrow klass value can never be zero [v2]

[Coleen Phillimore]

> The code for RedefineVerifyMark in redefinition replaces the OopHandle mirror so that the verification has the right mirror, but it really should just copy it.  Replacing an OopHandle in the ClassLoaderData didn't set the has_modified_oops flag so GC wasn't noticing that this handle is old.
> 
> Tested with tier1-4 and tier6 in progress (linux-x64 and windows-x64 done).

Coleen Phillimore has updated the pull request incrementally with one additional commit since the last revision:

  Kim's offline improvements.

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/11444/files
  - new: https://git.openjdk.org/jdk/pull/11444/files/2f8d5517..483da5e5

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=11444&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=11444&range=00-01

  Stats: 9 lines in 3 files changed: 0 ins; 3 del; 6 mod
  Patch: https://git.openjdk.org/jdk/pull/11444.diff
  Fetch: git fetch https://git.openjdk.org/jdk pull/11444/head:pull/11444

PR: https://git.openjdk.org/jdk/pull/11444