Sped up JavaScript iBench by 70%, the sort page by 88%.

        * kjs/array_object.h: Add array-specific sort functions.
        * kjs/array_object.cpp:
        (compareByStringForQSort): Added.
        (ArrayInstanceImp::sort): Added.
        (compareWithCompareFunctionForQSort): Added.
        (ArrayProtoFuncImp::call): Use ArrayInstanceImp::sort if the object being
	sorted is actually an array.

        * kjs/object.h: Add argumentsPropertyName.
        * kjs/object.cpp: Add argumentsPropertyName.
        * kjs/function.cpp:
        (FunctionImp::FunctionImp): Use argumentsPropertyName to avoid making a UString.
        (FunctionImp::call): Ditto.
        (ActivationImp::ActivationImp): Ditto.
        * kjs/function_object.cpp: (FunctionObjectImp::construct): Ditto.

        * kjs/ustring.h: Added compare function for -1/0/+1 comparison.
        * kjs/ustring.cpp: (KJS::compare): Added.


git-svn-id: http://svn.webkit.org/repository/webkit/trunk@2736 268f45cc-cd09-0410-ab3c-d52691b4dbfc