main/vim: add workaround for bug in vim's LDFLAGS modification

Starting with abuild-3.8.0_rc1, vim no longer builds with the default LDFLAGS value provided in /etc/abuild.conf. This is due to LDFLAGS modifications performed by vim's build system.

See https://github.com/vim/vim/issues/8181

With this commit --as-needed is no longer the last linker option. Not sure if this is relevant or not.

main/vim/APKBUILD

@@ -29,6 +29,9 @@ source="$pkgname-$pkgver.tar.gz::https://github.com/vim/vim/archive/v$pkgver.tar
 #   8.0.0056-r0:
 #     - CVE-2016-1248
 
+# workaround for https://github.com/vim/vim/issues/8181
+export LDFLAGS="-Wl$LDFLAGS"
+
 prepare() {
 	# Read vimrc from /etc/vim
 	echo '#define SYS_VIMRC_FILE "/etc/vim/vimrc"' >> src/feature.h