RFR: 8273314: Add tier4 test groups

[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}. I have excluded `vmTestbase` and `hotspot:tier4,` because they take 10+ hours on my highly parallel machine. I have also excluded `applications` from `hotspot:tier4`, because they require test dependencies (e.g. jcstress).

Sample run:


==============================
Test summary
==============================
   TEST                                              TOTAL  PASS  FAIL ERROR   
>> jtreg:test/hotspot/jtreg:tier4                      426   425     1     0 <<
>> jtreg:test/jdk:tier4                               2891  2885     4     2 <<
   jtreg:test/langtools:tier4                            0     0     0     0   
   jtreg:test/jaxp:tier4                                 0     0     0     0   
==============================

real	64m13.994s
user	1462m1.213s
sys	39m38.032s


There are interesting test failures on my machine, which I would address separately.

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

Commit messages:
 - Add tier4 test groups

Changes: https://git.openjdk.java.net/jdk/pull/5357/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=5357&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8273314
  Stats: 22 lines in 4 files changed: 22 ins; 0 del; 0 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