RFR: 8339783: Implementation of JEP 479: Remove the Windows 32-bit x86 Port [v4]

[Magnus Ihse Bursie]

> This is the implementation of [JEP 479: _Remove the Windows 32-bit x86 Port_](https://openjdk.org/jeps/479).
> 
> This is the summary of JEP 479:
>> Remove the source code and build support for the Windows 32-bit x86 port. This port was [deprecated for removal in JDK 21](https://openjdk.org/jeps/449) with the express intent to remove it in a future release.

Magnus Ihse Bursie has updated the pull request with a new target base due to a merge or a rebase. The pull request now contains seven commits:

 - Update VirtualMachineImpl_openProcess since it only needs to care about 64-bit
 - Merge branch 'master' into impl-JEP-479
 - Use #error for unknown CPU
 - Restore PLATFORM_CHECK_DEPRECATION
 - Remove FIXMEs on x86 code that will soon go away anyway
 - Remove FIXME for issue resolved in JDK-8343167
 - 8339783: Implementation of JEP 479: Remove the Windows 32-bit x86 Port

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Changes: https://git.openjdk.org/jdk/pull/21744/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=21744&range=03
  Stats: 1546 lines in 51 files changed: 66 ins; 1404 del; 76 mod
  Patch: https://git.openjdk.org/jdk/pull/21744.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/21744/head:pull/21744

PR: https://git.openjdk.org/jdk/pull/21744