RFR: 8299162: Refactor shared trampoline emission logic [v2]

[Xiaolin Zheng]

On Tue, 3 Jan 2023 03:38:55 GMT, Fei Yang <fyang at openjdk.org> wrote:

>> Xiaolin Zheng has updated the pull request incrementally with one additional commit since the last revision:
>> 
>>   __
>
> Looks good to me. Better to have another reviewer.

Thanks for taking the time to review this patch! @RealFYang @adinn @luhenry 
My local tests look okay on both AArch64 and RISC-V platforms.

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PR: https://git.openjdk.org/jdk/pull/11749