patch 8.2.1819: Vim9: Memory leak when using a closure

Problem:    Vim9: Memory leak when using a closure.
Solution:   Compute the mininal refcount in the funcstack.  Reenable disabled
            tests.
diff --git a/src/version.c b/src/version.c
index 5fdfeea..a953c09 100644
--- a/src/version.c
+++ b/src/version.c
@@ -751,6 +751,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1819,
+/**/
     1818,
 /**/
     1817,