RFR: 8340269: [s390x] TestLargeStub.java failure after 8338123

[Amit Kumar]

Fixes the test case; Ran tier1 with fastdebug-vm, didn't see any regression.

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

Commit messages:
 - fix

Changes: https://git.openjdk.org/jdk/pull/21033/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=21033&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8340269
  Stats: 2 lines in 1 file changed: 0 ins; 0 del; 2 mod
  Patch: https://git.openjdk.org/jdk/pull/21033.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/21033/head:pull/21033

PR: https://git.openjdk.org/jdk/pull/21033