Previews should exclude a property if its name is a symbol

test/inspector/runtime/evaluate-with-generate-preview.js

Index: test/inspector/runtime/evaluate-with-generate-preview.js
diff --git a/test/inspector/runtime/evaluate-with-generate-preview.js b/test/inspector/runtime/evaluate-with-generate-preview.js
index 5e747d5ab9ea695c78d1e4bf903f18438ecdea68..56bc1cdac379f8944c48696f96b1e39bf698a890 100644
--- a/test/inspector/runtime/evaluate-with-generate-preview.js
+++ b/test/inspector/runtime/evaluate-with-generate-preview.js
@@ -6,35 +6,39 @@ print("Tests that Runtime.evaluate will generate correct previews.");
 
 InspectorTest.addScript(
 `
+var sym = Symbol(123);
+
 Object.prototype[0] = 'default-first';
-var obj = {p1: {a:1}, p2: {b:'foo'}};
+var obj = {p1: {a:1}, p2: {b:'foo'}, p3: sym};
 Object.defineProperties(obj, {
-  p3: {
+  p4: {
     get() { return 2 }
   },
-  p4: {
+  p5: {
     set(x) { return x }
   },
-  p5: {
+  p6: {
     get() { return 2 },
     set(x) { return x }
   }
 });
+obj[sym] = 'baz';
 
 Array.prototype[0] = 'default-first';
-var arr = [,, 1, [2]];
+var arr = [,, 1, [2], sym];
 Object.defineProperties(arr, {
-  4: {
+  5: {
     get() { return 2 }
   },
-  5: {
+  6: {
     set(x) { return x }
   },
-  6: {
+  7: {
     get() { return 2 },
     set(x) { return x }
   }
 });
+arr[sym] = 'baz';
 `);
 
 InspectorTest.runTestSuite([