RFR: 8353188: C1: Clean up x86 backend after 32-bit x86 removal [v2]

[Vladimir Ivanov]

On Tue, 1 Apr 2025 07:58:27 GMT, Aleksey Shipilev <shade at openjdk.org> wrote:

>> Piece-wise cleanup of C1_LIRAssembler_x86, C1_MacroAssembler and related classes. C1 implements the bulk of arch-specific backend there. Major parts of this backend are already removed by #24274, this cleans up another large bulk, and hopefully most of it.
>> 
>> Additional testing:
>>  - [x] Linux x86_64 server fastdebug, `all`
>>  - [x] Linux x86_64 server fastdebug, `all` + `-XX:TieredStopAtLevel=1`
>
> Aleksey Shipilev has updated the pull request incrementally with one additional commit since the last revision:
> 
>   Review comments

Looks good.

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Marked as reviewed by vlivanov (Reviewer).

PR Review: https://git.openjdk.org/jdk/pull/24301#pullrequestreview-2733756865