RFR: 8286446: PPC64: fix crashes after JDK-8284161 (virtual threads preview) [v3]

[Richard Reingruber]

> With this change `java -version` succeeds with the devkit build also the standard build on a ppc64le box does not crash anymore.
> 
> Also tier1 tests don't look too bad.

Richard Reingruber 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 11 additional commits since the last revision:

 - Impl. generate_jfr_write_checkpoint() after JDK-8286480
 - Merge branch 'master' into fix_ppc_after_virtual_threads_integration
 - Martin's feedback
 - frame::patch_pc
 - frame::get_oop_map
 - Initialize new frame members
 - Fix Continuation::is_cont_barrier_frame
 - Fix ppc StubGenerator
 - TemplateInterpreterGenerator::generate_Continuation_doYield_entry
 - Fingerprinter::do_type_calling_convention
 - ... and 1 more: https://git.openjdk.java.net/jdk/compare/f0a6c870...c92b1b57

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

Changes:
  - all: https://git.openjdk.java.net/jdk/pull/8617/files
  - new: https://git.openjdk.java.net/jdk/pull/8617/files/ed466a24..c92b1b57

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jdk&pr=8617&range=02
 - incr: https://webrevs.openjdk.java.net/?repo=jdk&pr=8617&range=01-02

  Stats: 7286 lines in 198 files changed: 4222 ins; 2135 del; 929 mod
  Patch: https://git.openjdk.java.net/jdk/pull/8617.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/8617/head:pull/8617

PR: https://git.openjdk.java.net/jdk/pull/8617