RFR: 8304846: Provide a shared utility to dump generated classes defined via Lookup API [v7]

[Mandy Chung]

> This implements a shared utility to dump generated classes defined as normal/hidden classes via `Lookup` API.   This replaces the implementation in `LambdaMetaFactory` and method handle implementation that dumps the hidden class bytes on disk for debugging.   
> 
> For classes defined via `Lookup::defineClass`, `Lookup::defineHiddenClass` and `Lookup::defineHiddenClassWithClassData`, by default they will be dumped to the path specified in `-Djava.lang.invoke.Lookup.dumpClasses=<dumpDir>` 
> 
> The hidden classes generated for lambdas, `LambdaForms` and method handle implementation use non-default dumper so that they can be controlled via a separate system property and path as in the current implementation.
> 
> To dump lambda proxy classes, set this system property:
>    -Djdk.internal.lambda.dumpProxyClasses=<dumpDir>
> 
> To dump LambdaForms and method handle implementation, set this system property:
>    -Djava.lang.invoke.MethodHandle.DUMP_CLASS_FILES=true
>    
> P.S. `ProxyClassesDumper` is renamed to `ClassFileDumper` but for some reason, it's not shown as rename.

Mandy Chung has updated the pull request incrementally with one additional commit since the last revision:

  comments from Remi

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/13182/files
  - new: https://git.openjdk.org/jdk/pull/13182/files/2eeb7b04..120bc2f1

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=13182&range=06
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=13182&range=05-06

  Stats: 8 lines in 1 file changed: 0 ins; 2 del; 6 mod
  Patch: https://git.openjdk.org/jdk/pull/13182.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/13182/head:pull/13182

PR: https://git.openjdk.org/jdk/pull/13182