Propagate the Int48 stuff into the prediction propagator.
https://bugs.webkit.org/show_bug.cgi?id=121132

Reviewed by Mark Hahnenberg.
        
This still has no effect on codegen since Int48 still looks like a Double right now.

* bytecode/ExitKind.cpp:
(JSC::exitKindToString):
* bytecode/ExitKind.h:
* bytecode/SpeculatedType.cpp:
(JSC::speculationFromValue):
* bytecode/SpeculatedType.h:
(JSC::isMachineIntSpeculation):
(JSC::isMachineIntSpeculationExpectingDefined):
(JSC::isMachineIntSpeculationForArithmetic):
* dfg/DFGGraph.cpp:
(JSC::DFG::Graph::dump):
* dfg/DFGGraph.h:
(JSC::DFG::Graph::addShouldSpeculateMachineInt):
(JSC::DFG::Graph::mulShouldSpeculateInt32):
(JSC::DFG::Graph::mulShouldSpeculateMachineInt):
(JSC::DFG::Graph::negateShouldSpeculateMachineInt):
(JSC::DFG::Graph::hasExitSite):
* dfg/DFGNode.h:
(JSC::DFG::Node::shouldSpeculateMachineInt):
(JSC::DFG::Node::shouldSpeculateMachineIntForArithmetic):
(JSC::DFG::Node::shouldSpeculateMachineIntExpectingDefined):
(JSC::DFG::Node::canSpeculateInt48):
* dfg/DFGNodeFlags.h:
(JSC::DFG::nodeCanSpeculateInt48):
* dfg/DFGPredictionPropagationPhase.cpp:
(JSC::DFG::PredictionPropagationPhase::propagate):



git-svn-id: http://svn.webkit.org/repository/webkit/trunk@155499 268f45cc-cd09-0410-ab3c-d52691b4dbfc