https://bugs.webkit.org/show_bug.cgi?id=68500

Reviewed by Oliver Hunt.
        
This adds support for compiling constructors to the DFG. It's a
1% speed-up on V8, mostly due to a 6% speed-up on early-boyer.
It's also a 13% win on access-binary-trees, but it's neutral in
the SunSpider and Kraken averages.

* dfg/DFGByteCodeParser.cpp:
(JSC::DFG::ByteCodeParser::parseBlock):
* dfg/DFGCapabilities.h:
(JSC::DFG::mightCompileFunctionForConstruct):
(JSC::DFG::canCompileOpcode):
* dfg/DFGNode.h:
* dfg/DFGOperations.cpp:
* dfg/DFGOperations.h:
* dfg/DFGPropagator.cpp:
(JSC::DFG::Propagator::propagateNodePredictions):
(JSC::DFG::Propagator::performNodeCSE):
* dfg/DFGSpeculativeJIT.cpp:
(JSC::DFG::SpeculativeJIT::compile):
* runtime/Executable.cpp:
(JSC::FunctionExecutable::compileOptimizedForConstruct):
(JSC::FunctionExecutable::compileForConstructInternal):
* runtime/Executable.h:
(JSC::FunctionExecutable::compileForConstruct):
(JSC::FunctionExecutable::compileFor):
(JSC::FunctionExecutable::compileOptimizedFor):



git-svn-id: http://svn.webkit.org/repository/webkit/trunk@95672 268f45cc-cd09-0410-ab3c-d52691b4dbfc