fix for empty dsm directory, create Makefile with empty dist and distdir rules

Makefile.am

@@ -63,8 +63,6 @@ if STARPU_BUILD_SC_HYPERVISOR
 SUBDIRS += sc_hypervisor
 endif
 
-DIST_SUBDIRS = $(SUBDIRS)
-
 pkgconfigdir = $(libdir)/pkgconfig
 pkgconfig_DATA = libstarpu.pc starpu-1.0.pc starpu-1.1.pc starpu-1.2.pc starpu-1.3.pc
 

configure.ac

@@ -420,6 +420,9 @@ if test x$dsm_included != xyes; then
         if test x$enable_dsm = xyes; then
                 AC_MSG_ERROR(StarPU DSM library generation needs DSM source in STARPU/dsm subdirectory)
         fi
+	mkdir -p dsm
+	echo "dist:" > ./dsm/Makefile
+	echo "distdir:" >> ./dsm/Makefile
         enable_dsm=no
 fi