apkbuild-cpan: add detection for perl modules with native code

so we get arch set properly

apkbuild-cpan.in

@@ -249,6 +249,10 @@ sub do_depends {
 		$text =~ s/^pkgdesc=\"([^\"]*)\"$/pkgdesc=\"$abstract\"/mg or
 			die "Can't find cpandepends line in APKBUILD";
 	}
+	if (length(`find $metaprefix -name '*.xs'`)) {
+		$text =~ s/^arch=\"([^\"]*)\"$/arch="all"/mg or
+			die "Can't find arch line in APKBUILD";
+	}
 	if ($license ne 'unknown') {
 		$text =~ s/^license=\"([^\"]*)\"$/license=\"$license\"/mg or
 			die "Can't find license line in APKBUILD";