Issue #16504: Catch SyntaxErrors raised by tokenizer in IDLE.

Patch by Roger Serwy.
diff --git a/Misc/NEWS b/Misc/NEWS
index 08d3e36..d13a406 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -182,6 +182,9 @@
 Library
 -------
 
+- Issue #16504: IDLE now catches SyntaxErrors raised by tokenizer. Patch by
+  Roger Serwy.
+
 - Issue #16618: Make glob.glob match consistently across strings and bytes
   regarding leading dots.  Patch by Serhiy Storchaka.