RFR: 8366940: Test compiler/loopopts/superword/TestAliasingFuzzer.java timed out

[Emanuel Peter]

`TestAliasingFuzzer.java` generates 30 subtests for every run. They are randomized. Some vectorize and execute faster, some fail to vectorize and execute slower.

Hence, some natural variance in the duration is expected.
On most machines, it seems the variance in "Running Tests" is about 30-50sec (total test time about 35-70sec). But on some machines (macosx-x64-debug), the execution time is a bit slower: 60-100 in "Running Tests", with some outliers at 110+sec. These occasionally trip the 120sec timeout, and when they trip it, they somehow cause the harness to take an excessive 9+min to shut everything down.

Solutions:
- Option 1: generate fewer tests in `TestAliasingFuzzer.java`. Would be sad, the test has now found 2 real bugs within 2 weeks.
- Option 2: increase test timeout. That is what I'll do. Because the "outliers" that caused the timeouts were not far from all other cases on the same platform, and so they are acceptable.

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Commit messages:
 - JDK-8366940

Changes: https://git.openjdk.org/jdk/pull/27257/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=27257&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8366940
  Stats: 2 lines in 1 file changed: 0 ins; 0 del; 2 mod
  Patch: https://git.openjdk.org/jdk/pull/27257.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/27257/head:pull/27257

PR: https://git.openjdk.org/jdk/pull/27257