[DO NOT LAND] Set @@toStringTag for DOM object prototypes

LayoutTests/inspector/console/console-dir-expected.txt

 CONSOLE MESSAGE: line 9: test1,test2
 CONSOLE MESSAGE: line 10: [object NodeList]
 CONSOLE MESSAGE: line 11: [object XPathResult]
 CONSOLE MESSAGE: line 21: [object Object]
 CONSOLE MESSAGE: line 24: function () {}
 CONSOLE MESSAGE: line 28: [object Object]
 CONSOLE MESSAGE: line 31: [object Object]
 CONSOLE MESSAGE: line 32: [object Object]
 CONSOLE MESSAGE: line 34: function __proto__() { [native code] }
 CONSOLE MESSAGE: line 39: [object Uint8Array]
 Tests that console logging dumps proper messages.
 
 console-dir.html:9 Array[2]
     0: "test1"
     1: "test2"
     length: 2
     __proto__: Array[0]
 console-dir.html:10 NodeList[1]
     0: html
     length: 1
+    Symbol(Symbol.toStringTag): "NodeList"
     __proto__: NodeList
 console-dir.html:11 XPathResult
     invalidIteratorState: false
     resultType: 4
+    Symbol(Symbol.toStringTag): "XPathResult"
     __proto__: XPathResult
 console-dir.html:21 Object
     "": ""
     "  ": "  "
     " a b ": " a b "
     $foo5_: 0
     "a↵↵b↵c": "a↵↵b↵c"
     c d: "c d"
     negZero: -0
     __proto__: Object
@@ skipping 22 matching lines @@
     __proto__: function Empty() {}
     <function scope>
         No Scopes
 console-dir.html:39 Uint8Array[400000000]
     [0 … 99999999]
     [100000000 … 199999999]
     [200000000 … 299999999]
     [300000000 … 399999999]
     __proto__: Uint8Array