[jdk17u-dev] RFR: 8008243: Zero: Implement fast bytecodes [v2]

[Aleksey Shipilev]

> Clean backport to improve Zero performance. The rationale for backport is the same as for mainline. Given that Zero is used to implement the JVM on emerging platforms that are still rather slow themselves, it makes sense to make Zero quantifiably faster. Even 10% improvement means more than 2 hours a day worth of CPU time.
> 
> This backport requires a follow-up to fix some platforms:
>   [8277485](https://bugs.openjdk.org/browse/JDK-8277485): Zero: Fix _fast_{i,f}access_0 bytecodes handling 
> 
> We still have `RewriteBytecodes` to get the original behavior if more bugs appear.
> 
> Additional testing:
>  - [x] Linux x86_64 Zero `make bootcycle-images`

Aleksey Shipilev has updated the pull request with a new target base due to a merge or a rebase. The incremental webrev excludes the unrelated changes brought in by the merge/rebase. The pull request contains two additional commits since the last revision:

 - Merge branch 'master' into JDK-8008243-zero-fast-bytecodes
 - Backport e4362007da8e40c076493364df91cf85960a03e7

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

Changes:
  - all: https://git.openjdk.org/jdk17u-dev/pull/924/files
  - new: https://git.openjdk.org/jdk17u-dev/pull/924/files/eadfa8f2..6f1c7017

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk17u-dev&pr=924&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk17u-dev&pr=924&range=00-01

  Stats: 22160 lines in 300 files changed: 18281 ins; 1959 del; 1920 mod
  Patch: https://git.openjdk.org/jdk17u-dev/pull/924.diff
  Fetch: git fetch https://git.openjdk.org/jdk17u-dev pull/924/head:pull/924

PR: https://git.openjdk.org/jdk17u-dev/pull/924