[aarch64-port-dev ] RFR: 8223173: Implement fast class initialization checks on AARCH64

[Dmitrij Pochepko]

Hi all,

please review patch for enhancement: JDK-8223173 - Implement fast class 
initialization checks on AARCH64

CR: https://bugs.openjdk.java.net/browse/JDK-8223173
webrev: http://cr.openjdk.java.net/~dpochepk/8223173/webrev.01/

This patch follows x86-64 patch (JDK-8223213) and later bugfix 
(JDK-8225106). Also, leading nop generation in C1 is moved from 
build_frame method to verified_entry method to follow x86_64 
implementation and use clinit_barrier correctly (see invocation of 
clinit_barrier in hotspot/share/c1/c1_LIRAssembler.cpp)

Original performance issue reported by JDK-8219233 is resolved (x3 
improvement for reported case on AARCH64).

Testing:

- hotspot jtreg tests both in release and fastdebug modes: no 
regressions found
- jck tests in release and fastdebug modes: no regressions found

Please review this fix for JDK 14. Once this is in, I'd like to request 
approval for backporting to JDK 13 since corresponding fixes for x86_64 
and PPC are in JDK 13 already, unless the community feels otherwise.

Thanks,
Dmitrij