Add a test to ensure data/source files are not marked as executable.

tests/non-executable-files-with-executable-bit.test

@@ -0,0 +1,21 @@
+#!/bin/sh
+
+echo -n "testing files for executable bits that shouldn't be executable ... "
+
+find * -executable -type f | \
+	grep -vE "compile|config\.(guess|status|sub)|configure|depcomp|install-sh|libtool|missing" | # Ignore autotools output \
+	grep -vE "*\.test|src(/\.libs)?/(e?speak-ng|.*\.so\..*)" | # Ignore built programs and libraries \
+	grep -vE "*.\.sh|tools/emoji" | # Ignore helper scripts \
+	grep -vE "src/ucd-tools/tools/(.*\.py|mkencodingtable)" | # Ignore ucd-tools helper scripts \
+	tee tests/non-executable-files-with-executable-bit.check > /dev/null
+
+if [ -s tests/non-executable-files-with-executable-bit.check ] ; then
+	echo "found"
+	cat tests/non-executable-files-with-executable-bit.check
+	false
+else
+	rm tests/non-executable-files-with-executable-bit.check
+	echo "none found"
+	true
+fi
+