RFR: 8341584: Test java/foreign/TestUpcallStress.java intermittent timeout with -Xcomp

[SendaoYan]

Hi all,
Test `java/foreign/TestUpcallStress.java` intermittent timeout with -Xcomp, and this test use a very precise race, thus `-Xcomp` probably will never trigger the problematic use-case. So this test not suitable for -Xcomp mode.I add `@requires vm.compMode != "Xcomp"` to exclude from Xcomp testing and remove this test from `ProblemList-Xcomp.txt`.
Trivial fix, test-fix only, no risk.

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Commit messages:
 - 8341584: Test java/foreign/TestUpcallStress.java intermittent timeout with -Xcomp

Changes: https://git.openjdk.org/jdk/pull/21512/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=21512&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8341584
  Stats: 2 lines in 2 files changed: 1 ins; 1 del; 0 mod
  Patch: https://git.openjdk.org/jdk/pull/21512.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/21512/head:pull/21512

PR: https://git.openjdk.org/jdk/pull/21512