patch 8.2.3617: ":verbose pwd" does not mention 'autochdir' was applied

Problem:    ":verbose pwd" does not mention 'autochdir' was applied.
Solution:   Remember the last chdir was done by 'autochdir'.  (issue #9142)
diff --git a/src/buffer.c b/src/buffer.c
index 31f902d..29cfb8a 100644
--- a/src/buffer.c
+++ b/src/buffer.c
@@ -1899,7 +1899,10 @@
     if ((starting == 0 || test_autochdir)
 	    && curbuf->b_ffname != NULL
 	    && vim_chdirfile(curbuf->b_ffname, "auto") == OK)
+    {
 	shorten_fnames(TRUE);
+	last_chdir_reason = "autochdir";
+    }
 }
 #endif