[10] RFR(M): 8185976: PPC64: Implement MulAdd and SquareToLen intrinsics

[Gustavo Serra Scalet]

Hi,

Could you please review this specific PPC64 change to hotspot? By implementing these intrinsics I noticed a small improvement with microbenchmarks analysis. On SpecJVM2008's crypto.rsa benchmark, only when backporting to JDK8 an improvement was noticed.

JBS: https://bugs.openjdk.java.net/browse/JDK-8185976
Webrev: https://gut.github.io/openjdk/webrev/JDK-8185976/webrev/

Motivation for this implementation: https://twitter.com/ijuma/status/698309312498835457

Best regards,
Gustavo Serra Scalet