Don't OSR exit just because a string is a rope

Don't OSR exit just because a string is a rope
https://bugs.webkit.org/show_bug.cgi?id=104621

Reviewed by Michael Saboff.

Slight SunSpider speed-up at around the 0.7% level. This patch does the obvious
thing of calling a slow path to resolve ropes rather than OSR exiting if the
string is a rope.

* dfg/DFGAbstractState.cpp:
(JSC::DFG::AbstractState::execute):
* dfg/DFGArrayMode.h:
(JSC::DFG::ArrayMode::getIndexedPropertyStorageMayTriggerGC):
(ArrayMode):
* dfg/DFGCSEPhase.cpp:
(JSC::DFG::CSEPhase::putStructureStoreElimination):
* dfg/DFGOperations.cpp:
* dfg/DFGOperations.h:
* dfg/DFGSpeculativeJIT.cpp:
(JSC::DFG::SpeculativeJIT::compileGetIndexedPropertyStorage):
* dfg/DFGSpeculativeJIT.h:
(JSC::DFG::SpeculativeJIT::callOperation):

git-svn-id: https://svn.webkit.org/repository/webkit/trunk@137247 268f45cc-cd09-0410-ab3c-d52691b4dbfc