initial thread != primordial thread confuses attach tests (LinuxThreads only)

In b59 the launcher was changed to create a new thread to act as the java primordal thread. This breaks the attach mechanism on Linux releases that use the old LinuxThread library (newer distributions that use NTPL are not impacted). As a result the following tests fail:

    com/sun/tools/attach/BasicTests.sh
    com/sun/tools/attach/PermissionTests.sh
    com/sun/tools/attach/ProviderTests.sh
    sun/tools/jstack/Basic.sh
    sun/tools/jmap/Basic.sh
    com/sun/jdi/ProcessAttachTest.sh