Use AC_MSG_NOTICE so e.g. "configure --silent" is still silent.

expat/configure.ac

@@ -330,7 +330,7 @@ AC_CONFIG_FILES([run.sh], [chmod +x run.sh])
 AC_OUTPUT
 
 
-cat <<EOF
+AC_MSG_NOTICE([
 
 Automake flags (can be overridden by user flags):
   [AM_CPPFLAGS]: ${AM_CPPFLAGS}
@@ -343,4 +343,4 @@ User flags (override Automake flags on conflict):
        CFLAGS: ${CFLAGS}
      CXXFLAGS: ${CXXFLAGS}
       LDFLAGS: ${LDFLAGS}
-EOF
+])