make the tests run for cross-compiled windows

when compiling with mingw .exe must be added to the binaries
and cmp will find difference in the line endings when running those
binaries under wine, so use diff instead there.

tests/test-defs.sh

@@ -47,7 +47,7 @@ cd "$testsubdir" \
 
 echo "=== Running test $progname"
 
-CMP="${CMP-cmp}"
+DIFF="${DIFF-diff}"
 
 use_valgrind=${USE_VALGRIND-1}
 valgrind_path=$(which valgrind 2> /dev/null)
@@ -86,6 +86,10 @@ run_output_test()
 		REDIR_OUTPUT="| tee \"${TEST_OUTPUT}.out\""
 	fi
 
+	if [ -f ${top_builddir}/${TEST_COMMAND}.exe ]; then
+		TEST_COMMAND=${TEST_COMMAND}.exe
+	fi
+
 	if [ $use_valgrind -eq 1 ] ; then
 		eval valgrind --tool=memcheck \
 			--trace-children=yes \
@@ -114,9 +118,9 @@ run_output_test()
 		fi
 	fi
 
-	if ! "$CMP" -s "${top_builddir}/${TEST_OUTPUT}.expected" "${TEST_OUTPUT}.out" ; then
+	if ! "$DIFF" -w "${top_builddir}/${TEST_OUTPUT}.expected" "${TEST_OUTPUT}.out" ; then
 		echo "ERROR: \"${TEST_COMMAND} $@\" (${TEST_OUTPUT}) failed (set VERBOSE=1 to see full output):" 1>&2
-		(cd "${CURDIR}" ; set -x ; diff "${top_builddir}/${TEST_OUTPUT}.expected" "$testsubdir/${TEST_OUTPUT}.out")
+		(cd "${CURDIR}" ; set -x ; diff -wu "${top_builddir}/${TEST_OUTPUT}.expected" "$testsubdir/${TEST_OUTPUT}.out")
 		echo "cp \"$testsubdir/${TEST_OUTPUT}.out\" \"${top_builddir}/${TEST_OUTPUT}.expected\"" 1>&2
 
 		err=1