jsdouble d; LL_L2D(d, v); dbl = JS_NewDouble(cx, d);
dbl = JS_NewDouble(cx, (jsdouble)v);
JAM_DOUBLE(JSContext *cx, const int64 &v, jsdouble *dbl){   jsdouble d;   LL_L2D(d, v);   dbl = JS_NewDouble(cx, d);   return DOUBLE_TO_JSVAL(dbl);}