some class loading/initialization might case sun.awt.shell.Win32ShellFolder2$KnownFolderDefinition::<clinit> to hang. we have observed it running applications/ctw/Modules.java (which loads and compiles all available class) test on windows-x64

"main" #1 prio=5 os_prio=0 tid=0x000000f3b2325000 nid=0x13fc waiting on condition [0x000000f3b298d000]
   java.lang.Thread.State: WAITING (parking)
at jdk.internal.misc.Unsafe.park(java.base@10-internal/Native Method)
- parking to wait for <0x000000072ff2de60> (a java.util.concurrent.FutureTask)
at java.util.concurrent.locks.LockSupport.park(java.base@10-internal/LockSupport.java:194)
at java.util.concurrent.FutureTask.awaitDone(java.base@10-internal/FutureTask.java:447)
at java.util.concurrent.FutureTask.get(java.base@10-internal/FutureTask.java:190)
at sun.awt.shell.Win32ShellFolderManager2$ComInvoker.invoke(java.desktop@10-internal/Win32ShellFolderManager2.java:584)
at sun.awt.shell.ShellFolder.invoke(java.desktop@10-internal/ShellFolder.java:519)
at sun.awt.shell.ShellFolder.invoke(java.desktop@10-internal/ShellFolder.java:505)
at sun.awt.shell.Win32ShellFolder2.getLibraries(java.desktop@10-internal/Win32ShellFolder2.java:1290)
at sun.awt.shell.Win32ShellFolder2.access$000(java.desktop@10-internal/Win32ShellFolder2.java:75)
at sun.awt.shell.Win32ShellFolder2$KnownFolderDefinition.<clinit>(java.desktop@10-internal/Win32ShellFolder2.java:190)
at jdk.internal.misc.Unsafe.ensureClassInitialized0(java.base@10-internal/Native Method)
at jdk.internal.misc.Unsafe.ensureClassInitialized(java.base@10-internal/Unsafe.java:1042)
at sun.hotspot.tools.ctw.Compiler.compileClass(Compiler.java:74)