[jdk8u-dev] RFR: 8185348: Major performance regression in GetMethodDeclaringClass and other JVMTI Method functions [v2]

[Zhengyu Gu]

> Please review this patch for the parity of Oracle's [JDK-8185348](https://bugs.openjdk.org/browse/JDK-8185348).
> 
> Oracle's patch is non-public. This patch is based on @sspitsyn's comments in JDK-8185348 and consistent with JDK9's implementation.
> 
> Before patch, slowjvmti test case from JDK-8185348:
> 16366ms
> 
> After patch:
> 3ms

Zhengyu Gu 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 two additional commits since the last revision:

 - Merge branch 'master' into JDK-8348228
 - 8348228: Major performance regression in GetMethodDeclaringClass and other JVMTI Method functions

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

Changes:
  - all: https://git.openjdk.org/jdk8u-dev/pull/656/files
  - new: https://git.openjdk.org/jdk8u-dev/pull/656/files/d6115500..44c3342a

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk8u-dev&pr=656&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk8u-dev&pr=656&range=00-01

  Stats: 1479 lines in 60 files changed: 985 ins; 293 del; 201 mod
  Patch: https://git.openjdk.org/jdk8u-dev/pull/656.diff
  Fetch: git fetch https://git.openjdk.org/jdk8u-dev.git pull/656/head:pull/656

PR: https://git.openjdk.org/jdk8u-dev/pull/656