[PATCH 2/4] maint: update m4-latest* symlinks during upload

[Eric Blake]

Avoid the situation we had for several years where m4-latest.tar.xz
pointed to m4-1.4.17.tar.xz in spite of m4-1.4.18.tar.xz existing.
https://lists.gnu.org/archive/html/m4-discuss/2021-05/msg00003.html

* cfg.mk (GNUPLOADFLAGS): Update *-latest symlinks during gnupload.
---
 cfg.mk | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/cfg.mk b/cfg.mk
index b7f62d60..eb629b4b 100644
--- a/cfg.mk
+++ b/cfg.mk
@@ -36,6 +36,9 @@ config_h_header = "m4\.h"
 # Hash of NEWS contents, to ensure we don't add entries to wrong section.
 old_NEWS_hash = 9abe4a58cebb45c4b980db88e9f4b3c9

+# Update m4-latest.tar.* symlinks during 'make stable/beta'.
+GNUPLOADFLAGS = --symlink-regex
+
 # Indent only with spaces.
 sc_prohibit_tab_based_indentation:
  @re='^ *    '                                               \
-- 
2.31.1