RFR(M): 8224826: Implement fast class initialization checks on PPC64

[Gustavo Romero]

Hi Martin,

On 06/06/2019 09:27 AM, Doerr, Martin wrote:
> please review the rebased and updated version (after JDK-8225106):
> 
> http://cr.openjdk.java.net/~mdoerr/8224826_ppc64_fast_clinit/webrev.01/ 

Change looks good.

I also tested the 'release' and 'fastdebug' builds in different modes
(Interpreter, C1 TieredStopAtLevel={2,3}, and C2). For 'release' I checked the
speedups using the microbench from Claes [1] and observed significant speedups
(~10x) in the static member/block initialization.

Best regards,
Gustavo

[1] https://bugs.openjdk.java.net/browse/JDK-8219233