RFR: 8343452: Incorrect WINDOWS build variable is used in macroAssembler_x86.cpp

[duke]

On Tue, 5 Nov 2024 12:21:58 GMT, theoweidmannoracle <duke at openjdk.org> wrote:

> From JBS:
> 
>> HotSpot VM build macro defines _WINDOWS env variable only.
>> call_clobbered_gp_registers() and call_clobbered_xmm_registers() incorrectly use WINDOWS (without underscore).
>> RSI and RDI are missing from list of clobbered register on windows due to that and may cause issue when calling native code which modifies them.
>> 
>> AMM register are less affected because all XMM registers are listed as clobbered.
>> 
>> The code was added by [JDK-8283327](https://bugs.openjdk.org/browse/JDK-8283327) changes in JDK 19.

@theoweidmannoracle 
Your change (at version 93a01ee4af11aa27c49c999b6de8a1a4592241a6) is now ready to be sponsored by a Committer.

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PR Comment: https://git.openjdk.org/jdk/pull/21901#issuecomment-2461509537