Make sure that a Slider doesn't crash in 0x0 environment (flutter#177882)

This is my attempt to handle
flutter#6537 for the Slider widget.

Author: ahmedsameha1

packages/flutter/test/material/slider_test.dart

@@ -5490,4 +5490,17 @@ void main() {
       paints..circle(x: 800.0 - sliderPadding, y: 300.0, color: theme.colorScheme.primary),
     );
   });
+
+  testWidgets('Slider does not crash at zero area', (WidgetTester tester) async {
+    await tester.pumpWidget(
+      MaterialApp(
+        home: Scaffold(
+          body: Center(
+            child: SizedBox.shrink(child: Slider(value: 1, onChanged: (_) {})),
+          ),
+        ),
+      ),
+    );
+    expect(tester.getSize(find.byType(Slider)), Size.zero);
+  });
 }