win32-msvc2015: Fix LNK2019: unresolved external symbol

Fix LNK2019: unresolved external symbol "private: static void __cdecl QTJSC::MarkedArgumentBuffer::operator delete(void *,unsigned int)" (??3MarkedArgumentBuffer@QTJSC@@CAXPAXI@Z) referenced in function __unwindfunclet$??0JSGlobalData@QTJSC@@aae@_N@Z$22

Remove private "void* MarkerArgumentBuffer::operator new(size_t,
void*);" declaration as it is an overload with user specific
arguments, ie not one that will ever be supplied by the compiler. Also
remove "void MarkerArgumentBuffer::operator delete(void*, size_t);" as
it does not make sense to supply both that and "static void* operator
new(size_t size)". It is this latter overload that somehow trips the
GA version of Visual Studio 2015 (GA).

Change-Id: I47eea4322feac12f75f80e7858b9602a4036e562

src/3rdparty/javascriptcore/JavaScriptCore/runtime/ArgList.h

@@ -170,9 +170,6 @@ namespace JSC {
 
         void* operator new[](size_t);
         void operator delete[](void*);
-
-        void* operator new(size_t, void*);
-        void operator delete(void*, size_t);
     };
 
     class ArgList {

src/3rdparty/webkit/Source/JavaScriptCore/runtime/ArgList.h

@@ -172,9 +172,6 @@ namespace JSC {
 
         void* operator new[](size_t);
         void operator delete[](void*);
-
-        void* operator new(size_t, void*);
-        void operator delete(void*, size_t);
     };
 
     class ArgList {