Reviewed by Sam "That doesn't look like what I thought it looks like" Weinig.
        
        Beefed up the JSValuePtr class and removed some non-JSValuePtr dependencies
        on JSImmediate, in prepapration for making JSImmediate an implementation
        detail of JSValuePtr.
        
        SunSpider reports no change.

        * interpreter/Interpreter.cpp:
        (JSC::Interpreter::privateExecute):
        * jit/JIT.cpp:
        (JSC::JIT::privateCompileMainPass):
        * jit/JITArithmetic.cpp:
        (JSC::JIT::compileFastArith_op_mod):
        * runtime/JSGlobalObjectFunctions.cpp:
        (JSC::globalFuncParseInt): Updated for interface changes.

        * runtime/JSImmediate.h:
        (JSC::JSValuePtr::JSValuePtr):
        * runtime/JSValue.h:
        (JSC::JSValuePtr::):
        (JSC::jsImpossibleValue):
        (JSC::jsNull):
        (JSC::jsUndefined):
        (JSC::jsBoolean):
        (JSC::JSValuePtr::encode):
        (JSC::JSValuePtr::decode):
        (JSC::JSValuePtr::JSValuePtr):
        (JSC::JSValuePtr::operator bool):
        (JSC::JSValuePtr::operator==):
        (JSC::JSValuePtr::operator!=):
        (JSC::JSValuePtr::isUndefined):
        (JSC::JSValuePtr::isNull): Changed jsImpossibleValue(), jsNull(),
        jsUndefined(), and jsBoolean() to operate in terms of JSValuePtr instead
        of JSImmediate.

        * wtf/StdLibExtras.h:
        (WTF::bitwise_cast): Fixed up for clarity.



git-svn-id: http://svn.webkit.org/repository/webkit/trunk@43121 268f45cc-cd09-0410-ab3c-d52691b4dbfc