Unreviewed build fix for building JSC with DFG_ENABLE_DEBUG_PROPAGATION_VERBOSE enabled in DFGCommon.h.
Fixes the case where the argument node in fixupNode is freed due to the Vector storage being reallocated.

* dfg/DFGFixupPhase.cpp:
(JSC::DFG::FixupPhase::fixupNode):


git-svn-id: http://svn.webkit.org/repository/webkit/trunk@140227 268f45cc-cd09-0410-ab3c-d52691b4dbfc