build: Add a test suite infrastructure

test/Makefile.am

@@ -0,0 +1,16 @@
+## Process this file with automake to produce Makefile.in
+
+# Set default values for user variables
+CFLAGS = -Wall -Wextra -Wno-unused-variable -Wno-unused-parameter
+
+AM_CPPFLAGS = \
+	-I$(top_builddir) \
+	-isystem $(top_srcdir)/include/bsd/ \
+	-include $(top_builddir)/config.h \
+	-DLIBBSD_OVERLAY -DLIBBSD_DISABLE_DEPRECATED \
+	-D__REENTRANT
+
+check_PROGRAMS = \
+	$(nil)
+
+TESTS = $(check_PROGRAMS)