RFR: 8286191: misc tests fail due to JDK-8285987 [v2]

[Matthias Baesken]

> The isMusl method had to be handled in test/lib-test/jdk/test/lib/TestMutuallyExclusivePlatformPredicates.java .
> Additionally, the vm.musl predicate seem not to be available in the langtools tests.

Matthias Baesken 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 four additional commits since the last revision:

 - Merge remote-tracking branch 'origin/master' into JDK-8286191
 - remove from ProblemList
 - Merge remote-tracking branch 'origin/master' into JDK-8286191
 - JDK-8286191

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

Changes:
  - all: https://git.openjdk.java.net/jdk/pull/8556/files
  - new: https://git.openjdk.java.net/jdk/pull/8556/files/afdc9797..96f508df

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jdk&pr=8556&range=01
 - incr: https://webrevs.openjdk.java.net/?repo=jdk&pr=8556&range=00-01

  Stats: 515 lines in 30 files changed: 194 ins; 107 del; 214 mod
  Patch: https://git.openjdk.java.net/jdk/pull/8556.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/8556/head:pull/8556

PR: https://git.openjdk.java.net/jdk/pull/8556