RFR: 8259948: Aarch64: Add cast nodes for Aarch64 Neon backend [v12]

[Eric Liu]

On Fri, 22 Oct 2021 09:59:29 GMT, Wang Huang <whuang at openjdk.org> wrote:

>> * In this issue, we plan to complete all missing implementation for aarch64 neon backend. For example, cast from Byte to Long, cast from Long to Byte, and so on.
>> * It may be a solver of JDK-8269866, or part of it.
>
> Wang Huang has updated the pull request incrementally with one additional commit since the last revision:
> 
>   fix styles

LGTM

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Marked as reviewed by eliu (Author).

PR: https://git.openjdk.java.net/jdk/pull/4839