RFR: 8356945: jdk/jfr/event/os/TestProcessStart failed on Windows Subsystem for Linux

[Chihiro Ito]

Currently, when this test is run on Windows Subsystem for Linux, dir is executed as an external process.
However, dir is a cmd.exe command, and dir.exe does not exist, so the test fails as shown below.

----------System.out:(0/0)----------
----------System.err:(19/2649)*----------
java.io.IOException: Cannot run program "dir" (in directory "D:\\dev\\jdk\\build\\windows-x86_64-server-release\\test-support\\jtreg_test_jdk_jdk_jfr_event_os_TestProcessStart_java\\scratch\\0\."): CreateProcess error=2, The system cannot find the file specified

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Commit messages:
 - 8356945: jdk/jfr/event/os/TestProcessStart failed on Windows

Changes: https://git.openjdk.org/jdk/pull/25227/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=25227&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8356945
  Stats: 4 lines in 1 file changed: 2 ins; 1 del; 1 mod
  Patch: https://git.openjdk.org/jdk/pull/25227.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/25227/head:pull/25227

PR: https://git.openjdk.org/jdk/pull/25227