RFR: 8304425: ClassHierarchyResolver from Reflection [v2]

[Chen Liang]

> Add API to explore Class Hierarchy with a `ClassLoader` or a `Lookup` with proper privileges, with tests.
> 
> This addition is useful in case classes at runtime are not loaded from the system class loader, such as Proxy. This is also useful to APIs that generate bytecode with a `Lookup` object, such as a custom single-abstract-method class implementations from a method handle.
> 
> See https://mail.openjdk.org/pipermail/classfile-api-dev/2023-March/000249.html as well.
> 
> Current questions, which I wish to discuss with @asotona:
> 1. Should the resolver fail fast on `IllegalAccessException` from the lookup? This usually indicates the hierarchy resolver is set up improperly, and proceeding may simply yield verification errors in class loading that are hard to track. For bytecode-generating APIs, throwing access errors for the Lookup eagerly is also more preferable than later silent generation failure.
> 2. Whether the default resolver should be reading from jrt alone, reflection alone, or jrt then reflection. I personally believe reflection alone is more reliable, for classes may redefined with instrumentation or jfr, which may not be reflected in the system resources.
> 3. In addition, I don't think chaining system class loader reflection after system resource retrieval is really meaningful: is there any case where reflection always works while the system resource retrieval always fails?

Chen Liang has updated the pull request incrementally with one additional commit since the last revision:

  Make lookup based resolver throw on illegal access eagerly

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/13082/files
  - new: https://git.openjdk.org/jdk/pull/13082/files/04dfe62d..e74eb13d

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=13082&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=13082&range=00-01

  Stats: 19 lines in 3 files changed: 12 ins; 1 del; 6 mod
  Patch: https://git.openjdk.org/jdk/pull/13082.diff
  Fetch: git fetch https://git.openjdk.org/jdk pull/13082/head:pull/13082

PR: https://git.openjdk.org/jdk/pull/13082