[10] RFR(S): 8185969: PPC64: Improve VSR support to use up to 64 registers

[Gustavo Serra Scalet]

Hi,

Could you please review this specific PPC64 change to hotspot? The aim of these changes is to allow a more complete usage of VSR. I make use of these interfaces on an instrinsic that I plan to send next but I decided to separate this change and send it first.

JBS: https://bugs.openjdk.java.net/browse/JDK-8185969
Webrev: https://gut.github.io/openjdk/webrev/JDK-8185969/webrev/

Best regards,
Gustavo Serra Scalet