Issue #16350: Fix zlib decompressor handling of unused_data with multiple calls to decompress() after EOF.

Patch by Serhiy Storchaka.
diff --git a/Misc/NEWS b/Misc/NEWS
index 883bd93..b2ad14b 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -137,6 +137,10 @@
 Library
 -------
 
+- Issue #16350: zlib.Decompress.decompress() now accumulates data from
+  successive calls after EOF in unused_data, instead of only saving the argument
+  to the last call. Patch by Serhiy Storchaka.
+
 - Issue #12759: sre_parse now raises a proper error when the name of the group
   is missing.  Initial patch by Serhiy Storchaka.