[jdk11u-dev] RFR: 8313796: AsyncGetCallTrace crash on unreadable interpreter method pointer [v2]

[Ben Taylor]

> Backport [8313796](https://bugs.openjdk.org/browse/JDK-8313796) to resolve a hotspot crash. Passes jtreg tier 1-4 tests.
> 
> This change required the following modifications:
> - Remove riscv code, as the riscv port is not present in jdk 11
> - Replace `nullptr` with `NULL` to accommodate older C++ standards/compilers

Ben Taylor 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 one additional commit since the last revision:

  8313796: AsyncGetCallTrace crash on unreadable interpreter method pointer
  
  Reviewed-by: coleenp, aph, stuefe

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

Changes:
  - all: https://git.openjdk.org/jdk11u-dev/pull/2079/files
  - new: https://git.openjdk.org/jdk11u-dev/pull/2079/files/98163382..ae012a4e

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk11u-dev&pr=2079&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk11u-dev&pr=2079&range=00-01

  Stats: 1569 lines in 6 files changed: 1169 ins; 46 del; 354 mod
  Patch: https://git.openjdk.org/jdk11u-dev/pull/2079.diff
  Fetch: git fetch https://git.openjdk.org/jdk11u-dev.git pull/2079/head:pull/2079

PR: https://git.openjdk.org/jdk11u-dev/pull/2079