sys-apps/portage: install tmpfiles.d to create /var/tmp/portage

This ensures the directory is created at boot, and prevents other users
from creating it before emerge is run.

Bug: https://bugs.gentoo.org/853283
Closes: https://github.com/gentoo/gentoo/pull/27871
Signed-off-by: Mike Gilbert <floppym@gentoo.org>

sys-apps/portage/files/portage-tmpdir.conf

@@ -0,0 +1 @@
+d /var/tmp/portage 0775 portage portage

sys-apps/portage/portage-3.0.38.1-r1.ebuild

@@ -217,7 +217,7 @@ python_install_all() {
 		esetup.py "${targets[@]}"
 	fi
 
-	dotmpfiles "${FILESDIR}"/portage-ccache.conf
+	dotmpfiles "${FILESDIR}"/portage-{ccache,tmpdir}.conf
 
 	# Due to distutils/python-exec limitations
 	# these must be installed to /usr/bin.

sys-apps/portage/portage-9999.ebuild

@@ -212,7 +212,7 @@ python_install_all() {
 		esetup.py "${targets[@]}"
 	fi
 
-	dotmpfiles "${FILESDIR}"/portage-ccache.conf
+	dotmpfiles "${FILESDIR}"/portage-{ccache,tmpdir}.conf
 
 	# Due to distutils/python-exec limitations
 	# these must be installed to /usr/bin.