On Windows & Linux, using JSVALUE32_64, EncodedJSValue is returned in registers, but JSValue is not.

Reviewed by Oliver Hunt.

JavaScriptCore: 

* API/JSCallbackFunction.cpp:
(JSC::JSCallbackFunction::call):
* API/JSCallbackFunction.h:
* API/JSCallbackObject.h:
* API/JSCallbackObjectFunctions.h:
(JSC::::call):
* JavaScriptCore.exp:
* interpreter/Interpreter.cpp:
(JSC::Interpreter::executeCall):
* jit/JITStubs.cpp:
(JSC::DEFINE_STUB_FUNCTION):
* jit/JITStubs.h:
* jsc.cpp:
(functionPrint):
(functionDebug):
(functionGC):
(functionVersion):
(functionRun):
(functionLoad):
(functionCheckSyntax):
(functionSetSamplingFlags):
(functionClearSamplingFlags):
(functionReadline):
(functionQuit):
* runtime/ArrayConstructor.cpp:
(JSC::callArrayConstructor):
(JSC::arrayConstructorIsArray):
* runtime/ArrayPrototype.cpp:
(JSC::arrayProtoFuncToString):
(JSC::arrayProtoFuncToLocaleString):
(JSC::arrayProtoFuncJoin):
(JSC::arrayProtoFuncConcat):
(JSC::array...