The scenario that caused JDK-8362237 was when the cause exception has no stack trace while the main exception does. The SourceLauncherStackTraceTest removed all stack traces with `-XX:-StackTraceInThrowable`, which is not quite the desired scenario.

Since Java 7 exceptions can be constructed with no stack traces, so we can use platform APIs to accomplish that in SourceLauncherTest itself. Meanwhile SourceLauncherStackTraceTest might still be meaningful to ensure the source launcher works with the no stack trace VM flag.