RFR: 8349107: Remove RMI finalizers [v2]

[Brent Christian]

> 3 finalizers in RMI code can be removed, as they do not perform meaningful cleanup.
> 
> **`jdk.naming.rmi/share/classes/com/sun/jndi/rmi/registry/RegistryContext`**
> 
> `RegistryContext.finalize()` just calls `close()`. The `close()` method does not perform any cleanup per se, but rather "helps the garbage collector" by setting `environment` and `registry` to `null`.
> 
> 
> **`jdk.naming.rmi/share/classes/com/sun/jndi/rmi/registry/RegistryContext.BindingEnumeration`**
> 
> `BindingEnumeration.finalize()` simply calls `close()` on the `ctx` field, itself a `RegistryContext` (and `close()` just "helps the GC.")
> 
> 
> **`src/java.rmi/share/classes/sun/rmi/log/LogInputStream`**
> 
> `LogInputStream` tracks its length with an int field, `length`. If `length` ever becomes == 0, `LogInputStream`'s methods will return without doing anything.
> 
> The finalizer calls `close()`, which just sets length = 0.
> 
> By the time a `LogInputStream` becomes unreachable and is finalized, it's a moot point whether length == 0, as no more methods can be called.
> If anything, this finalizer could cause a bug. If a `LogInputStream` were to became unreachable while a method were still running, the finalizer could set the length to 0 while method code is still running and expecting a length != 0.
> It's possible that there is a very long standing bug that `close()` should be calling `in.close()`, in which case this evaluation will need to be revisited.

Brent Christian 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 four additional commits since the last revision:

 - Merge branch 'master' into rmF10Nnow
 - Remove finalizer from RMI LogInputStream
 - Remove finalizer from RMI RegistryContext.BindingEnumeration
 - Remove finalizer from RMI RegistryContext

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/23406/files
  - new: https://git.openjdk.org/jdk/pull/23406/files/387aa517..b2257898

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=23406&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=23406&range=00-01

  Stats: 40438 lines in 2951 files changed: 18380 ins; 12171 del; 9887 mod
  Patch: https://git.openjdk.org/jdk/pull/23406.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/23406/head:pull/23406

PR: https://git.openjdk.org/jdk/pull/23406