RFR: 8338344: Test TestPrivilegedMode.java intermittent fails java.lang.NoClassDefFoundError: jdk/test/lib/Platform

[SendaoYan]

Hi,
  Test `test/hotspot/jtreg/testlibrary_tests/ir_framework/tests/TestPrivilegedMode.java` always fails by ours daily CI with fastdebug build, but I can't reproduce this fail standalone.
  When the test fails `java.lang.NoClassDefFoundError: jdk/test/lib/Platform`, the `jdk/test/lib/Platform.class` locate in `/var/tmp/tone/run/jtreg/jt-work/jtreg/hotspot_jtreg/classes/5/test/lib`, but `bootClassPath` [set as](https://github.com/openjdk/jdk/blob/master/test/hotspot/jtreg/compiler/lib/ir_framework/driver/TestVMProcess.java#L103) `/var/tmp/tone/run/jtreg/jt-work/jtreg/hotspot_jtreg/classes/5/testlibrary_tests/ir_framework/tests/TestPrivilegedMode.d` 

bootClassPath += File.pathSeparator + Utils.TEST_CLASSES;


I think `bootClassPath` should set as `Utils.TEST_CLASS_PATH`.

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

Commit messages:
 - 8338344: Test TestPrivilegedMode.java intermittent fails java.lang.NoClassDefFoundError: jdk/test/lib/Platform

Changes: https://git.openjdk.org/jdk/pull/20576/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=20576&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8338344
  Stats: 3 lines in 2 files changed: 1 ins; 0 del; 2 mod
  Patch: https://git.openjdk.org/jdk/pull/20576.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/20576/head:pull/20576

PR: https://git.openjdk.org/jdk/pull/20576