https://bugs.webkit.org/show_bug.cgi?id=105576

Rubber stamped by Gavin Barraclough.

Changed the use of -1 as a pointer value in the JITs to be the constant unusedPointer defined in the
new file jit/UnusedPointer.h.  Made it's value 0xd1e7beef, which is a bad pointer on most architectures
because it is odd, and to distinguish it from other common values.

* GNUmakefile.list.am:
* JavaScriptCore.xcodeproj/project.pbxproj:
* dfg/DFGRepatch.cpp:
(JSC::DFG::dfgResetGetByID):
(JSC::DFG::dfgResetPutByID):
* dfg/DFGSpeculativeJIT32_64.cpp:
(JSC::DFG::SpeculativeJIT::cachedGetById):
(JSC::DFG::SpeculativeJIT::cachedPutById):
* dfg/DFGSpeculativeJIT64.cpp:
(JSC::DFG::SpeculativeJIT::cachedGetById):
(JSC::DFG::SpeculativeJIT::cachedPutById):
* jit/JIT.h:
* jit/JITPropertyAccess.cpp:
(JSC::JIT::resetPatchGetById):
(JSC::JIT::resetPatchPutById):
* jit/JITPropertyAccess32_64.cpp:
(JSC::JIT::resetPatchGetById):
(JSC::JIT::resetPatchPutById):
* jit/JITWriteBarrier.h:
(JSC::JITWriteBarrierBase::clearToUnusedPointer):
(JSC::JITWriteBarrierBase::get):
* jit/UnusedPointer.h: Added.


git-svn-id: http://svn.webkit.org/repository/webkit/trunk@138308 268f45cc-cd09-0410-ab3c-d52691b4dbfc