Change Item 12, Clarify Rationale, p. 23

Replace the last paragraph of the Rationale section with the following text:

The NoHeapRealtimeThread class is provided in order to allow time-critical threads to execute in preference to the garbage collector given appropriate assignment of execution eligibility. The memory access and assignment semantics of the NoHeapRealtimeThread are designed to guarantee that the execution of such threads does not lead to an inconsistent heap state.