Build the benchmarks only if a configure option is enabled.

Makefile.am

 ACLOCAL_AMFLAGS = -I m4 -I ${VARNISHAPI_DATAROOTDIR}/aclocal
 
-SUBDIRS = src src/tests/bench
+if WANT_BENCH
+  MAYBE_BENCH = src/tests/bench
+endif
+SUBDIRS = src $(MAYBE_BENCH)
 
 DISTCHECK_CONFIGURE_FLAGS = \
 	VMOD_DIR='$${libdir}/varnish/vmods'

configure.ac

@@ -112,6 +112,13 @@ if test "x$enable_debugging" != "xno"; then
 		[])
 fi
 
+AC_ARG_ENABLE(benchmarks,
+	AS_HELP_STRING([--enable-benchmarks],
+	[build benchmark utilities for the search algorithms (default is NO)]),
+	[],
+	[enable_benchmarks=no])
+AM_CONDITIONAL([WANT_BENCH], [test "x$enable_benchmarks" != "xno"])
+
 AC_CONFIG_FILES([
 	Makefile
 	src/Makefile