Set ThreadPlanCallFunction to private in ConstructorSetup. This fixes a problem...

Set ThreadPlanCallFunction to private in ConstructorSetup.  This fixes a problem on Linux where 'continue' was misfiring after an expression evaluation when stopped at a breakpoint.  The problem was that InferiorCallMmap was not setting its ThreadPlanCallFunction to private and so the completion of that thread plan appeared to be the stop reason and therefore the 'continue' operation failed to step over the breakpoint.  The SetPrivate call is being put in ThreadPlanCallFunction rather than InferiorCallMmap to make the solution more general.

llvm-svn: 169618