Make sure all files under the new shared dir are included in make dist.

git-svn-id: svn://svn.valgrind.org/valgrind/trunk@13868 a5019735-40e9-0310-863c-91ae7b9d1cf9
diff --git a/configure.ac b/configure.ac
index ece5faa..b1e567a 100644
--- a/configure.ac
+++ b/configure.ac
@@ -2996,6 +2996,7 @@
    exp-bbv/tests/arm-linux/Makefile
    exp-dhat/Makefile
    exp-dhat/tests/Makefile
+   shared/Makefile
 ])
 AC_CONFIG_FILES([coregrind/link_tool_exe_linux],
                 [chmod +x coregrind/link_tool_exe_linux])