RFR: 8317368: [JVMCI] SIGSEGV in JVMCIEnv::initialize_installed_code on libgraal [v3]

[Tom Rodriguez]

> This fixes some lurking issues with JVMCI and nmethod related both BarrierSetNMethod and the garbage collection of nmethods.  In particular the stack walking in c2v_iterateFrames visits many frames and needs a KeepStackGCProcessedMark for safety.  Additionally, JVMCI interacts with nmethods in complex ways and needs some sort of strong root during these interactions.  A new JavaThread field has been added that mirrors the way JVMTI keeps nmethods alive.

Tom Rodriguez has updated the pull request incrementally with one additional commit since the last revision:

  Comment updates

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/17714/files
  - new: https://git.openjdk.org/jdk/pull/17714/files/429a769f..2a2142fb

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=17714&range=02
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=17714&range=01-02

  Stats: 3 lines in 2 files changed: 1 ins; 0 del; 2 mod
  Patch: https://git.openjdk.org/jdk/pull/17714.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/17714/head:pull/17714

PR: https://git.openjdk.org/jdk/pull/17714