Decouple Block from Node

+/**
+ * Add the node type visibility settings table for blocks.
+ */
+function node_update_7007() {
+  $ret = array();
+
+  $schema = node_schema();
+  db_create_table($ret, 'node_block_visibility', $schema['node_block_visibility']);
+
+  return $ret;
+}

This is no good, you have to copy the schema array here as it was done in block.install. Otherwise, if the schema changes, the update would change as well which is bad because subsequent updates would fail. See http://drupal.org/node/150220 for details.

Otherwise, the patch looks great.

Xano: With Schema API as it stands, we may not use hook_schema() declarations in hook_update_N. Please read http://drupal.org/node/150220, the explanation there is as good as it can be explained, so I won't try to explain it here in the issue.

empty patch file?

According to the latest 8.x, node is no more dependency for block.
I was able to disable node module (which in standard installation was required by comment, forum and book), and enter block configuration page