RFR: 8318668: java/lang/management/MemoryMXBean/CollectionUsageThreshold.java fails with Xcomp

[Ramkumar Sunderbabu]

Trivial change to exclude the test from running with Xcomp flag.

The test fails because the number of GCs as reported by the MXBean doesn't match the expected number. This is due to the additional GC happening due to CodeCache crossing its threshold.
We could increase the code cache or restrict the specific compiler that fills the cache. But this will not completely eliminate the possibility as cache size could be overridden or the same failure can happen for a different compiler.

So, it is better to restrict the Xcomp flag as a whole.

Testing:
Only local testing done as it is trivial change. One run with Xcomp and another without any flags.

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Commit messages:
 - Excluding the test for Xcomp

Changes: https://git.openjdk.org/jdk/pull/22180/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=22180&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8318668
  Stats: 2 lines in 1 file changed: 0 ins; 0 del; 2 mod
  Patch: https://git.openjdk.org/jdk/pull/22180.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/22180/head:pull/22180

PR: https://git.openjdk.org/jdk/pull/22180