RFR: 8277328: jdk/jshell/CommandCompletionTest.java failures on Windows

[Jan Lahoda]

The `CommandCompletionTest.java#testUserHome` test picks an existing file or directory in the user's home directory, and uses it to validate the behavior of completion after '~/'. The test fails if the test picks a directory with space.

This is not solely a problem in the test - JShell does not handle paths with spaces. The proposed solution is to allow spaces in paths to be escaped with '', and adjust tests accordingly.

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Commit messages:
 - 8277328: jdk/jshell/CommandCompletionTest.java failures on Windows

Changes: https://git.openjdk.java.net/jdk/pull/6578/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=6578&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8277328
  Stats: 25 lines in 2 files changed: 17 ins; 0 del; 8 mod
  Patch: https://git.openjdk.java.net/jdk/pull/6578.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/6578/head:pull/6578

PR: https://git.openjdk.java.net/jdk/pull/6578