RFR: 8339783: Implement JEP 479: Remove the Windows 32-bit x86 Port [v30]

[David Holmes]

On Mon, 4 Nov 2024 20:42:59 GMT, Magnus Ihse Bursie <ihse at openjdk.org> wrote:

>> 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 incrementally with one additional commit since the last revision:
> 
>   fix: jvm_md.h was included, but not jvm.h...

I think you may be throwing the baby out with the bath water when it comes to `__stdcall`. It may be that 32-bit requires `__stdcall` but I don't see anything that states `__stdcall` is ONLY for 32-bit!

src/hotspot/os/windows/os_windows.cpp line 510:

> 508: // Thread start routine for all newly created threads.
> 509: // Called with the associated Thread* as the argument.
> 510: static unsigned thread_native_entry(void* t) {

Whoa! Hold on there. The `_stdcall` is required here and nothing to do with 32-bit. We use `begindthreadex` to start threads and the entry function is required to be `_stdcall`.
https://learn.microsoft.com/en-us/cpp/c-runtime-library/reference/beginthread-beginthreadex?view=msvc-170

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Changes requested by dholmes (Reviewer).

PR Review: https://git.openjdk.org/jdk/pull/21744#pullrequestreview-2417056020
PR Review Comment: https://git.openjdk.org/jdk/pull/21744#discussion_r1830259353