Cleanup of Calls to operationStrCat and operationNewArray and Use Constructor after...

Cleanup of Calls to operationStrCat and operationNewArray and Use Constructor after r117729
https://bugs.webkit.org/show_bug.cgi?id=87027

Reviewed by Oliver Hunt.

Change calls to operationStrCat and operationNewArray to provide the
pointer to the EncodedJSValue* data buffer instead of the ScratchBuffer
that contains it.  Added a ScratchBuffer::create() function.
This is a clean-up to r117729.

* dfg/DFGOperations.cpp:
* dfg/DFGSpeculativeJIT32_64.cpp:
(JSC::DFG::SpeculativeJIT::compile):
* dfg/DFGSpeculativeJIT64.cpp:
(JSC::DFG::SpeculativeJIT::compile):
* runtime/JSGlobalData.h:
(JSC::ScratchBuffer::create):
(JSC::ScratchBuffer::dataBuffer):
(JSC::JSGlobalData::scratchBufferForSize):

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@117860 268f45cc-cd09-0410-ab3c-d52691b4dbfc