patch 8.2.0489: Vim9: memory leaks

Problem:    Vim9: memory leaks.
Solution:   Free memory in the right place.  Add hints for using asan.
diff --git a/src/testdir/lsan-suppress.txt b/src/testdir/lsan-suppress.txt
index a3008bd..f3d62b9 100644
--- a/src/testdir/lsan-suppress.txt
+++ b/src/testdir/lsan-suppress.txt
@@ -9,3 +9,4 @@
 leak:libperl.so.*
 leak:libpython*.so.*
 leak:libruby*.so.*
+leak:libxcb*.so.*