Avoid UB in qjsnumbercoercion.h

We need to check for NaN before casting a double to an integer.

Pick-to: 6.2
Task-number: QTBUG-94068
Change-Id: Ib7bfab5ab2e24af950c8f8d7b32c7d411bd8cb71
Reviewed-by: Fabian Kosmale <fabian.kosmale@qt.io>

src/qml/common/qjsnumbercoercion.h

@@ -49,9 +49,13 @@ class QJSNumberCoercion
 {
 public:
     static constexpr int toInteger(double d) {
-        int i = static_cast<int>(d);
+        if (!equals(d, d))
+            return 0;
+
+        const int i = static_cast<int>(d);
         if (equals(i, d))
             return i;
+
         return QJSNumberCoercion(d).toInteger();
     }