patch 8.2.0149: maintaining a Vim9 branch separately is more work

Problem:    Maintaining a Vim9 branch separately is more work.
Solution:   Merge the Vim9 script changes.
diff --git a/src/viminfo.c b/src/viminfo.c
index 24cd4f7..b2b7ab2 100644
--- a/src/viminfo.c
+++ b/src/viminfo.c
@@ -1327,6 +1327,7 @@
 		    case VAR_SPECIAL: s = "XPL"; break;
 
 		    case VAR_UNKNOWN:
+		    case VAR_VOID:
 		    case VAR_FUNC:
 		    case VAR_PARTIAL:
 		    case VAR_JOB: