[jdk17u] RFR: 8271287: jdk/jshell/CommandCompletionTest.java fails with "lists don't have the same size expected"

[Thejasvi Voniadka]

This is a straight, clean backport of the following bug:

8271287: jdk/jshell/CommandCompletionTest.java fails with "lists don't have the same size expected"

The patch applies clean, and the test passes on all platforms.

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Commit messages:
 - Backport 71788c69dbae854331f3393044dab458c906045f

Changes: https://git.openjdk.java.net/jdk17u/pull/121/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk17u&pr=121&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8271287
  Stats: 9 lines in 1 file changed: 8 ins; 0 del; 1 mod
  Patch: https://git.openjdk.java.net/jdk17u/pull/121.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk17u pull/121/head:pull/121

PR: https://git.openjdk.java.net/jdk17u/pull/121