RFR: 8276796: gc/TestSystemGC.java large pages subtest fails with ZGC [v3]

[Aleksey Shipilev]

> ZGC would not start when it cannot allocate the heap with `-XX:+UseLargePages`. This makes the `UseLargePages` subtest fail on systems with (default) `nr_hugepages = 0`. It was exposed after [JDK-8269077](https://bugs.openjdk.java.net/browse/JDK-8269077) moved that test config from G1-specific to generic one.
> 
> While fixing this bug, I decided to massage a test a bit: make it consistently choosing the configuration based on GC availability, doing `UseLargePages` tests only for GCs that fall back to non-large pages if not available, added test IDs. This basically goes the other way JDK-8269077 went: put in the GC-specific configs.
> 
> Additional testing:
>  - [x] Linux x86_64 fastdebug, `gc/TestSystemGC.java` (runs all 5 configs)
>  - [x] Linux x86_64 fastdebug, `gc/TestSystemGC.java`, `TEST_VM_OPTS=-XX:+UseSerialGC` (runs 1 config)
>  - [x] Linux x86_64 fastdebug, `gc/TestSystemGC.java`, `TEST_VM_OPTS=-XX:+UseParallelGC` (runs 1 config)
>  - [x] Linux x86_64 fastdebug, `gc/TestSystemGC.java`, `TEST_VM_OPTS=-XX:+UseG1GC` (runs 1 config)
>  - [x] Linux x86_64 fastdebug, `gc/TestSystemGC.java`, `TEST_VM_OPTS=-XX:+UseShenandoahGC` (runs 1 config)
>  - [x] Linux x86_64 fastdebug, `gc/TestSystemGC.java`, `TEST_VM_OPTS=-XX:+UseZGC` (runs 1 config)

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 three additional commits since the last revision:

 - Merge branch 'master' into JDK-8276796-zgc-systemgc
 - Review comments
 - Fix

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

Changes:
  - all: https://git.openjdk.java.net/jdk/pull/6310/files
  - new: https://git.openjdk.java.net/jdk/pull/6310/files/15170896..21728b94

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jdk&pr=6310&range=02
 - incr: https://webrevs.openjdk.java.net/?repo=jdk&pr=6310&range=01-02

  Stats: 2906 lines in 76 files changed: 1432 ins; 1293 del; 181 mod
  Patch: https://git.openjdk.java.net/jdk/pull/6310.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/6310/head:pull/6310

PR: https://git.openjdk.java.net/jdk/pull/6310