RFR: 8259948: Aarch64: Add cast nodes for Aarch64 Neon backend [v4]

[Wu Yan]

On Fri, 3 Sep 2021 04:30:43 GMT, Eric Liu <eliu at openjdk.org> wrote:

> I tested in my local, a `bad AD file` due to the missing rule of `VectorReinterpret 4B`

Thanks, I'll add the rule of `VectorReinterpret 4B` in next commit.

-------------

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