DFG FixupPhase should have one common hook for knowing if a node is ever being speculated a certain way
https://bugs.webkit.org/show_bug.cgi?id=110650

Reviewed by Mark Hahnenberg.
        
Changes almost all calls to edge.setUseKind(kind) to be
setUseKindAndUnboxIfProfitable<kind>(edge). This will allow us to use the latter
as a hook for deciding which locals to unbox (webkit.org/b/110433).

* dfg/DFGFixupPhase.cpp:
(JSC::DFG::FixupPhase::fixupNode):
(FixupPhase):
(JSC::DFG::FixupPhase::setUseKindAndUnboxIfProfitable):
(JSC::DFG::FixupPhase::fixIntEdge):
(JSC::DFG::FixupPhase::fixDoubleEdge):
(JSC::DFG::FixupPhase::attemptToMakeIntegerAdd):



git-svn-id: http://svn.webkit.org/repository/webkit/trunk@143817 268f45cc-cd09-0410-ab3c-d52691b4dbfc