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* Improvements to memory management of various aspects of invocation
  records (aka call frames), greatly reducing memory pressure in a
  number of cases, especially in applications that produce and store a
  large number of closures. Up to 20% improvement to CORE.setting
  build time and ~10% peak memory use reduction observed.
* I/O memory buffers properly contribute to full collection criteria,
  reducing memory overhead required.
* Fix an occasional heap profiler crash, and prevent heap profiler
  from greatly reducing the number of full GC collections.
* Prevent specializer log slots from keeping alive, and so leaking,
  objects once specialized code has been produced.
* Fix regression in UTF8-C8 encoding.
* Fix build under (perhaps just older versions of) MSVC.

tools/build/NQP_REVISION

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-2016.12-87-g9c2f39c
+2016.12-89-ge3cf5bc