RFR: 8292640: C2: Remove unused scratch register usages on x86 [v3]

[Vladimir Ivanov]

On Tue, 23 Aug 2022 19:48:11 GMT, Vladimir Ivanov <vlivanov at openjdk.org> wrote:

>> (PR is dependent on #9932.)
>> 
>> Remove redundant scratch register usages in C2 generated code on x86. 
>> 
>> Stubs put constants in code cache, so they are RIP-relative addressable from generated code. It allows to save on scratch registers when accessing constants.  
>> 
>> Testing: hs-tier1 - hs-tier4
>
> Vladimir Ivanov has updated the pull request with a new target base due to a merge or a rebase. The pull request now contains seven commits:
> 
>  - Merge branch 'master' into rscratch.redundant
>  - redundant temps
>  - movptr
>  - 8292638: x86: Improve scratch register handling in VM stubs
>  - StubRoutines cleanup
>  - tabs
>  - x86: Improve handling of constants in trigonometric stubs

Thanks for the reviews, Vladimir.

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PR: https://git.openjdk.org/jdk/pull/9933