RFR: 8327964: Simplify BigInteger.implMultiplyToLen intrinsic [v3]

[Damon Fenacci]

On Tue, 19 Mar 2024 21:09:31 GMT, Yudi Zheng <yzheng at openjdk.org> wrote:

>> Moving array construction within BigInteger.implMultiplyToLen intrinsic candidate to its caller simplifies the intrinsic implementation in JIT compiler.
>
> Yudi Zheng has updated the pull request incrementally with one additional commit since the last revision:
> 
>   address comment.

`multiply_to_len` seems to be used by `generate_squareToLen` as well for aarch64 and riscv but `zlen` is still passed in a register.

https://github.com/openjdk/jdk/blob/870a6127cf54264c691f7322d775b202705c3bfa/src/hotspot/cpu/aarch64/stubGenerator_aarch64.cpp#L4710
https://github.com/openjdk/jdk/blob/870a6127cf54264c691f7322d775b202705c3bfa/src/hotspot/cpu/riscv/stubGenerator_riscv.cpp#L2881

I think it might work anyway but it might be better to adapt them if only for completeness.

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PR Review: https://git.openjdk.org/jdk/pull/18226#pullrequestreview-1960906919