Add bench for libcollection.

bench/Makefile

@@ -98,6 +98,14 @@ bench-sparsepp0:
 	@./bench-sparsepp.exe 42
 	@./bench-sparsepp.exe 43
 
+# LIBCOLLECTION shall point to the directory where the 'src' directory is.
+bench-libcollection:
+	if test -n "$${LIBCOLLECTION}" ; then make bench-libcollection0 ; else echo "Nothing to be done." ; fi
+
+bench-libcollection0:
+	$(CC) $(CFLAGS) $(CPPFLAGS) -I "$${LIBCOLLECTION}/include" -L "$${LIBCOLLECTION}" -static bench-libcollection.c -lcollectc -o bench-libcollection.exe
+	@./bench-libcollection.exe 20
+
 bench-plain:
 	$(CC) $(CFLAGS) $(CPPFLAGS) bench-plain-c.c -o bench-plain-c.exe
 	@./bench-plain-c.exe