Errored: OpenSmalltalk/opensmalltalk-vm#2210 (Cog - 561b065)

CogVM source as per VMMaker.oscog-eem.2824

Cog: Fix the crash when running tests in
ImageSegmentTest>>#testContextsShouldBeWritableToaFile (see
http://forum.world.st/corruption-of-PC-in-context-objects-or-not-tt5121662.html#none).
In mapping a machine code pc, a code compaction may occur. In this case return
through machine code is impossible without updating a C call stack return
address, since the machine code method that invoked this primitive could have
moved. So if this happens, map to an interpreter frame and return to the
interpreter.

Refactor CoInterpreter>>ceSendMustBeBooleanTo:interpretingAtDelta: to extract
CoInterpreter>>convertToInterpreterFrame:, Have CoInterpreterPrimitives>>
primitiveClone, primitiveInstVarAt, primitiveSlotAt monitor newMethod's header
and return to the interpreter if it has changed, indicating that a reclamation
affecting newMethod has occurred.
In V3 make sure that newMethod is set in jitted shallowCopy, instvarAt, slotAt:
(newMethod is assigned by default in Spur).

Again the split JIT/CoInterpreter design comes to the rescue in fixing a very
tricky issue, code moving underneath one. Being able to simply continue in the
interpreter (impossible in e.g. HPS) means the solution is relatively
straight-forward, and requires very little set-up.