Asserts in StackValue.getObject() due to bad type.

nsk tests:

nsk/sajdi/StackFrame/getValues/getvalues001
nsk/sajdi/StackFrame/thisObject/thisobj001

Stack trace:
#Exception in thread "main" sun.jvm.hotspot.utilities.AssertionFailure: type check
# at sun.jvm.hotspot.utilities.Assert.that(Assert.java:15)
# at sun.jvm.hotspot.runtime.StackValue.getObject(StackValue.java:40)
# at sun.jvm.hotspot.runtime.StackValueCollection.oopHandleAt(StackValueCollection.java:34)
# at sun.jvm.hotspot.jdi.StackFrameImpl.thisObject(StackFrameImpl.java:110)
# at nsk.sajdi.StackFrame.thisObject.thisobj001.checkFrame(thisobj001.java:190)
# at nsk.sajdi.StackFrame.thisObject.thisobj001.runIt(thisobj001.java:152)
# at nsk.sajdi.StackFrame.thisObject.thisobj001.run(thisobj001.java:26)
# at nsk.sajdi.StackFrame.thisObject.thisobj001.main(thisobj001.java:21)