patch 8.2.4345: <amatch> is expanded like a file name for DirChangedPre

Problem:    <amatch> is expanded like a file name for DirChangedPre.
Solution:   Do not expand <amatch>. (closes #9742)  Also for the User event.
diff --git a/src/autocmd.c b/src/autocmd.c
index 97b27ef..d1ecad9 100644
--- a/src/autocmd.c
+++ b/src/autocmd.c
@@ -2043,7 +2043,7 @@
     {
 	sfname = vim_strsave(fname);
 	// Don't try expanding FileType, Syntax, FuncUndefined, WindowID,
-	// ColorScheme, QuickFixCmd* or DirChanged
+	// ColorScheme, QuickFixCmd*, DirChanged and similar.
 	if (event == EVENT_FILETYPE
 		|| event == EVENT_SYNTAX
 		|| event == EVENT_CMDLINECHANGED
@@ -2061,7 +2061,9 @@
 		|| event == EVENT_OPTIONSET
 		|| event == EVENT_QUICKFIXCMDPOST
 		|| event == EVENT_DIRCHANGED
+		|| event == EVENT_DIRCHANGEDPRE
 		|| event == EVENT_MODECHANGED
+		|| event == EVENT_USER
 		|| event == EVENT_WINCLOSED)
 	{
 	    fname = vim_strsave(fname);