RFR: 8355585: Aarch64: Add aarch64 backend for Float16 vector operations [v4]

[Emanuel Peter]

On Wed, 21 May 2025 07:49:10 GMT, Bhavana Kilambi <bkilambi at openjdk.org> wrote:

>> Looks good. I'm assuming you've tested both SVE and Neon.
>
>> Looks good. I'm assuming you've tested both SVE and Neon.
> 
> Yes, this was tested on both SVE and Neon (N1/V1/V2 architectures).

@Bhavana-Kilambi I'm getting timeouts with your new test:
`compiler/vectorization/TestFloat16VectorOperations.java`

At least on `linux-aarch64-debug` and `windows-x64-debug`, but not all tests have completed yet, so more could be failing.

Not sure if it is relevant, but both had extra flag `-XX:-UseTLAB`, we add this flag in our additional stress testing.

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

PR Comment: https://git.openjdk.org/jdk/pull/25096#issuecomment-2896991985