RFR: 8351556: Optimize Location.locationFor/isModuleOrientedLocation [v2]

[Aleksey Shipilev]

> Leyden's JavacBenchApp benchmarks shows ~1% of time of the very first iteration is spent doing `Pattern.compile` in `Location.isModuleOrientedLocation`. Additionally, `Pattern.compile` becomes hot and requires JIT compilation, which eats CPU time. We can do better.
> 
> This improvement naturally spills over to `Location.locationFor`.
> 
> Things we do:
>  1. Avoid `putIfAbsent` on fast-path.
>  2. Lazily cache `Pattern` and reuse for all related paths.
>  3. Capture output/module flags ahead of time, instead of recomputing them.
>  4. (for interpreter/startup benefit) Use direct class type instead of interface.
> 
> There is also a little matching bug ([JDK-8351561](https://bugs.openjdk.org/browse/JDK-8351561)), which this performance improvement would retain.
> 
> Additional testing:
>  - [x] New regression test still works
>  - [x] New benchmark shows improvements
>  - [ ] Linux x86_64 server fastdebug, `langtools_all`

Aleksey Shipilev has updated the pull request incrementally with two additional commits since the last revision:

 - Also direct properties test
 - Touchups

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/23973/files
  - new: https://git.openjdk.org/jdk/pull/23973/files/08490e19..d58d2769

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=23973&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=23973&range=00-01

  Stats: 64 lines in 2 files changed: 59 ins; 0 del; 5 mod
  Patch: https://git.openjdk.org/jdk/pull/23973.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/23973/head:pull/23973

PR: https://git.openjdk.org/jdk/pull/23973