[dartdevc] Warning and shorting when trying to improperly modify JS Object's prototype chain.

See bugs:
* dart-lang/webdev#1133
* #43750

Change-Id: I0daa13ab56be5a2967241a5fcea63a32c0a5cde4
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/167220
Reviewed-by: Sigmund Cherem <[email protected]>
Reviewed-by: Nicholas Shahan <[email protected]>
Reviewed-by: Mark Zhou <[email protected]>
Commit-Queue: Mark Zhou <[email protected]>

Author: Markzipan

sdk/lib/_internal/js_dev_runtime/private/ddc_runtime/classes.dart

@@ -435,6 +435,13 @@ void _applyExtension(jsType, dartExtType) {
     return;
   }
 
+  if (JS('!', '# === #.Object', jsType, global_)) {
+    var extName = JS<String>('!', '#.name', dartExtType);
+    _warn(
+        "Attempting to install properties from non-Object type '$extName' onto the native JS Object.");
+    return;
+  }
+
   _installProperties(
       jsProto, dartExtType, JS('', '#[#]', jsProto, _extensionType));