[lworld] RFR: 8252040: [lworld] Execute compiler unit tests in random order

[Tobias Hartmann]

- Profiling of callee methods depends on execution order of unit tests. Execute tests in random order to increase
  coverage.
- At double field to test inline type
- Verify that expected NPEs are always thrown
- Fixed a test bug in TestLWorldProfiling.java (array element is not re-initialized and therefore NULL)
- Refactoring and removal of old, non-applicable TODOs

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Commit messages:
 - 8252040: [lworld] Execute compiler unit tests in random order

Changes: https://git.openjdk.java.net/valhalla/pull/154/files
 Webrev: https://webrevs.openjdk.java.net/valhalla/154/webrev.00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8252040
  Stats: 187 lines in 12 files changed: 14 ins; 8 del; 165 mod
  Patch: https://git.openjdk.java.net/valhalla/pull/154.diff
  Fetch: git fetch https://git.openjdk.java.net/valhalla pull/154/head:pull/154

PR: https://git.openjdk.java.net/valhalla/pull/154