https://bugs.webkit.org/show_bug.cgi?id=123302

Reviewed by Geoffrey Garen.
        
InlineStart was a special instruction that we would insert at the top of inlined code,
so that the backend could capture the OSR state of arguments to an inlined call. It used
to be that only the backend had this information, so this instruction was sort of an ugly
callback from the backend for filling in some data structures.
        
But in the time since when that code was written (two years ago?), we rationalized how
variables work. It's now the case that variables that the runtime must know about are
treated specially in IR (they are "flushed") and we know how we will represent them even
before we get to the backend. The last place that makes changes to their representation
is the StackLayoutPhase.
        
So, this patch gets rid of InlineStart, but keeps around the special meta-data that the
instruction had. Instead of handling the bookkeeping in the backend, we handle it in
StackLayoutPhase. This means that the DFG and FTL can share code for handling this
bookkeeping. This also means that now the FTL can compile code blocks that had inlining.
        
Of course, giving the FTL the ability to handle code blocks that had inlining means that
we're going to have new bugs. Sure enough, the FTL's linker didn't handle inline call
frames. This patch also fixes that.

* dfg/DFGAbstractInterpreterInlines.h:
(JSC::DFG::::executeEffects):
* dfg/DFGByteCodeParser.cpp:
(JSC::DFG::ByteCodeParser::handleInlining):
(JSC::DFG::ByteCodeParser::InlineStackEntry::InlineStackEntry):
* dfg/DFGClobberize.h:
(JSC::DFG::clobberize):
* dfg/DFGFixupPhase.cpp:
(JSC::DFG::FixupPhase::fixupNode):
* dfg/DFGGraph.h:
* dfg/DFGNode.h:
* dfg/DFGNodeType.h:
* dfg/DFGPredictionPropagationPhase.cpp:
(JSC::DFG::PredictionPropagationPhase::propagate):
* dfg/DFGSafeToExecute.h:
(JSC::DFG::safeToExecute):
* dfg/DFGSpeculativeJIT.cpp:
* dfg/DFGSpeculativeJIT.h:
* dfg/DFGSpeculativeJIT32_64.cpp:
(JSC::DFG::SpeculativeJIT::compile):
* dfg/DFGSpeculativeJIT64.cpp:
(JSC::DFG::SpeculativeJIT::compile):
* dfg/DFGStackLayoutPhase.cpp:
(JSC::DFG::StackLayoutPhase::run):
* ftl/FTLLink.cpp:
(JSC::FTL::link):



git-svn-id: http://svn.webkit.org/repository/webkit/trunk@158116 268f45cc-cd09-0410-ab3c-d52691b4dbfc