to be both speculative and non-speculative
https://bugs.webkit.org/show_bug.cgi?id=69321

Reviewed by Gavin Barraclough.
        
Removed m_isSpeculative and speculationCheck() from JITCodeGenerator.
This required moving emitBranch() to SpeculativeJIT, since it was
the main user of that field and method. Other than trvial clean-ups
in emitBranch(), the code is unchanged (and still has some disparity
between 64 and 32_64, and still lacks some obvious optimizations).

* dfg/DFGJITCodeGenerator.cpp:
* dfg/DFGJITCodeGenerator.h:
(JSC::DFG::JITCodeGenerator::JITCodeGenerator):
* dfg/DFGJITCodeGenerator32_64.cpp:
(JSC::DFG::JITCodeGenerator::fillDouble):
(JSC::DFG::JITCodeGenerator::fillJSValue):
* dfg/DFGJITCodeGenerator64.cpp:
(JSC::DFG::JITCodeGenerator::fillDouble):
(JSC::DFG::JITCodeGenerator::fillJSValue):
* dfg/DFGSpeculativeJIT.h:
(JSC::DFG::SpeculativeJIT::SpeculativeJIT):
* dfg/DFGSpeculativeJIT32_64.cpp:
(JSC::DFG::SpeculativeJIT::emitBranch):
* dfg/DFGSpeculativeJIT64.cpp:
(JSC::DFG::SpeculativeJIT::emitBranch):



git-svn-id: http://svn.webkit.org/repository/webkit/trunk@96661 268f45cc-cd09-0410-ab3c-d52691b4dbfc