toplevel: Unbreak Ada build [PR123490]

As written earlier, the config-ml.in change from the
--with-multi-buildlist patch broke build of Ada, Ada uses
RTSDIR = rts$(subst /,_,$(MULTISUBDIR))
and expects that the primary multilib will result in rts
rather than rts_. it results in after the --with-multi-buildlist
changes.

The following patch fixes it by restoring previous behavior for
ml_subdir / MULTISUBDIR such that for primary multilib it is
still empty rather than /.

2026-01-10  Jakub Jelinek  <jakub@redhat.com>

	PR ada/123490
	* config-ml.in: Restore ml_subdir being empty instead of /.
	for the primary multilib.

diff --git a/config-ml.in b/config-ml.in
index 22021a7fe3c8811e6ce1540ba1ac158e221d4c75..3b0440f3bd275f91c85fda12d7153373141e3fb5 100644 (file)
--- a/config-ml.in
+++ b/config-ml.in
@@ -615,7 +615,11 @@ fi
 
 if [ -z "${with_multisubdir}" ]; then
   ml_top_subdir=`${CC-gcc} --print-multi-directory 2>/dev/null`
-  ml_subdir=/$ml_top_subdir
+  if [ "$ml_top_subdir" = . ]; then
+    ml_subdir=
+  else
+    ml_subdir=/$ml_top_subdir
+  fi
   ml_builddotdot=
   : # ml_srcdotdot= # already set
 else