RFR: 8273314: Add tier4 test groups [v4]

[Aleksey Shipilev]

> During the review of JDK-8272914 that added hotspot:tier{2,3} groups, @iignatev suggested to create tier4 groups that capture all tests not in tiers{1,2,3}. 
> 
> Caveats:
>  - I excluded `applications` from `hotspot:tier4`, because they require test dependencies (e.g. jcstress).
>  - `jdk:tier4` only runs well with `JTREG_KEYWORDS=!headful` or reduced concurrency with `TEST_JOBS=1`, because headful tests cannot run in parallel
> 
> Sample run with `JTREG_KEYWORDS=!headful`:
> 
> 
> ==============================
> Test summary
> ==============================
>    TEST                                              TOTAL  PASS  FAIL ERROR   
>>> jtreg:test/hotspot/jtreg:tier4                     3585  3584     0     1 <<
>>> jtreg:test/jdk:tier4                               2893  2887     5     1 <<
>    jtreg:test/langtools:tier4                            0     0     0     0   
>    jtreg:test/jaxp:tier4                                 0     0     0     0   
> ==============================
> 
> real	699m39.462s
> user	6626m8.448s
> sys	1110m43.704s
> 
> 
> There are interesting test failures on my machine, which I would address separately.

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 five additional commits since the last revision:

 - Merge branch 'master' into JDK-8273314-tier4
 - Merge branch 'master' into JDK-8273314-tier4
 - Drop applications and fix the comment
 - Drop exceptions
 - Add tier4 test groups

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

Changes:
  - all: https://git.openjdk.java.net/jdk/pull/5357/files
  - new: https://git.openjdk.java.net/jdk/pull/5357/files/160c13c7..a5115a8d

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jdk&pr=5357&range=03
 - incr: https://webrevs.openjdk.java.net/?repo=jdk&pr=5357&range=02-03

  Stats: 14580 lines in 682 files changed: 9082 ins; 3191 del; 2307 mod
  Patch: https://git.openjdk.java.net/jdk/pull/5357.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/5357/head:pull/5357

PR: https://git.openjdk.java.net/jdk/pull/5357