Add option to disable tests building

Make optional the building of the `tests` target. This is specially
useful when targeting for platforms where the tests, as written today,
are not supported.

Author: gonzalolarralde

Makefile.am

@@ -12,6 +12,10 @@ if BUILD_OWN_KQUEUES
   MAYBE_KQUEUES = libkqueue
 endif
 
+if BUILD_TESTS
+  MAYBE_TESTS = tests
+endif
+
 SUBDIRS=						\
 	dispatch					\
 	$(MAYBE_PTHREAD_WORKQUEUES)	\
@@ -20,7 +24,7 @@ SUBDIRS=						\
 	os							\
 	private						\
 	src							\
-	tests
+	$(MAYBE_TESTS)
 
 EXTRA_DIST=					\
 	README.md				\

configure.ac

@@ -455,6 +455,13 @@ AC_COMPILE_IFELSE(
   [AC_DEFINE(HAVE_NORETURN_BUILTIN_TRAP, 1, [Define if __builtin_trap marked noreturn])]
 )
 
+#
+# Add option to avoid building tests
+#
+AC_ARG_ENABLE([build-tests],
+  [AS_HELP_STRING([--disable-build-tests], [Disable tests compilation])])
+AM_CONDITIONAL(BUILD_TESTS, [test "x$enable_build_tests" != "xno"])
+
 #
 # Generate Makefiles.
 #