RFR: 8333796: Add missing serialization functionality to sun.reflect.ReflectionFactory [v2]

[David M. Lloyd]

> Issue [JDK-8164908](https://bugs.openjdk.org/browse/JDK-8164908) added support for functionality required to continue to support IIOP and custom serializers in light of additional module-based restrictions on reflection. It was expected that these libraries would use `sun.misc.Unsafe` in order to access fields of serializable classes. However, with JEP 471, the methods necessary to do this are being removed.
> 
> To allow these libraries to continue to function, it is proposed to add two methods to `sun.reflect.ReflectionFactory` which will allow serialization libraries to acquire a method handle to generated `readObject`/`writeObject` methods which set or get the fields of the serializable class using the serialization `GetField`/`PutField` mechanism. These generated methods should be used by serialization libraries to serialize and deserialize classes which do not have a `readObject`/`writeObject` method or which use `ObjectInputStream.defaultReadObject`/`ObjectOutputStream.defaultWriteObject` to supplement default serialization.
> 
> It is also proposed to add methods which allow for the reading of serialization-specific private static final fields from classes which have them.
> 
> With the addition of these methods, serialization libraries no longer need to rely on `Unsafe` for serialization/deserialization activities.
> cc: @AlanBateman

David M. Lloyd has updated the pull request incrementally with two additional commits since the last revision:

 - Eliminate cache
 - Rework using facilities found in ObjectStreamClass
   
   This variation has the disadvantage of requiring a couple temporary arrays to be allocated each time the method handles are used.

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Changes:
  - all: https://git.openjdk.org/jdk/pull/19702/files
  - new: https://git.openjdk.org/jdk/pull/19702/files/e7334655..1d8f1b22

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=19702&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=19702&range=00-01

  Stats: 620 lines in 6 files changed: 187 ins; 427 del; 6 mod
  Patch: https://git.openjdk.org/jdk/pull/19702.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/19702/head:pull/19702

PR: https://git.openjdk.org/jdk/pull/19702