RFR: 8370579: PPC: fix inswri immediate argument order

[Manuel Hässig]

On Mon, 27 Oct 2025 14:10:24 GMT, Martin Doerr <mdoerr at openjdk.org> wrote:

>> This cleanup PR swaps and renames the immediate arguments of the two `insrwi` instruction macros in `ppc.ad` such that they correspond to the order and names in the manual. This involved swapping the arguments in all six usages. I hope this saves the next person trying to reason about this some confused hours.
>> 
>> Testing:
>>  - [x] Github Actions
>>  - [x] Running some relevant tests (`compiler/c2/TestCharShortByteSwap.java`, `jdk/java/lang/Short/ByteSwap.java`, `jdk/java/lang/Integer/BitTwiddle.java`, `compiler/codegen/Test6431242.java`) in qemu
>
> Looks good and tier1 has passed. Thanks for cleaning this up! The old code was really hard to read. Maybe @MBaesken can provide a 2nd review.

Thank you for testing and reviewing, @TheRealMDoerr & @MBaesken!

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PR Comment: https://git.openjdk.org/jdk/pull/27978#issuecomment-3455283367