[vector] Address review comments for AArch64 backend changes

[Paul Sandoz]

Hi Yang,

Including Andrew in case he is not monitoring this list as closely as others.

Just so I understand the changes to assembler_aarch64.cpp are due to updating aarch64-asmtest.py?

Otherwise, it's a shuffling of of neon instructions to a new file and updating the test to generate code containing those new instructions, as you say. 

I am not fully qualified to review on AArch64 but the approach looks good to me.

Paul.  

> On Jul 6, 2020, at 10:41 PM, Yang Zhang <Yang.Zhang at arm.com> wrote:
> 
> Hi,
> 
> Please help to review this patch that addresses review comments for Vector API AArch64 backend changes [1].
> 1. Seperate newly added NEON instructions to a new ad file
>   aarch64_neon.ad
> 2. Add assembler tests for NEON instructions. Trailing spaces
>   in the python script are also removed.
> 
> Webrev: http://cr.openjdk.java.net/~yzhang/vectorapi/vectorapi.neon_ad/webrev.00/
> 
> [1] https://mail.openjdk.java.net/pipermail/hotspot-compiler-dev/2020-May/038313.html
> 
> Regards
> Yang