Revert pg_relation_check_pages()

This reverts the following set of commits, following complaints about
the lack of portability of the central part of the code in bufmgr.c as
well as the use of partition mapping locks during page reads:
c780a7a9
f2b88396
b787d4ce
ce7f772c
60a51c6b

Per discussion with Andres Freund, Robert Haas and myself.

Bump catalog version.

Discussion: https://postgr.es/m/20201029181729.2nrub47u7yqncsv7@alap3.anarazel.de

1 files changed, 0 insertions, 56 deletions

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index ee721d258e0..87a6ba8d10f 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -26171,62 +26171,6 @@ SELECT convert_from(pg_read_binary_file('file_in_utf8.txt'), 'UTF8');
 
   </sect2>
 
-  <sect2 id="functions-data-sanity">
-   <title>Data Sanity Functions</title>
-
-   <para>
-    The functions shown in <xref linkend="functions-data-sanity-table"/>
-    provide ways to check the sanity of data files in the cluster.
-   </para>
-
-   <table id="functions-data-sanity-table">
-    <title>Data Sanity Functions</title>
-    <tgroup cols="1">
-     <thead>
-      <row>
-       <entry role="func_table_entry"><para role="func_signature">
-        Function
-       </para>
-       <para>
-        Description
-       </para></entry>
-      </row>
-     </thead>
-
-     <tbody>
-      <row>
-       <entry role="func_table_entry"><para role="func_signature">
-        <indexterm>
-         <primary>pg_relation_check_pages</primary>
-        </indexterm>
-        <function>pg_relation_check_pages</function> ( <parameter>relation</parameter> <type>regclass</type> [, <parameter>fork</parameter> <type>text</type> ] )
-        <returnvalue>setof record</returnvalue>
-        ( <parameter>path</parameter> <type>text</type>,
-        <parameter>failed_block_num</parameter> <type>bigint</type> )
-       </para>
-       <para>
-        Checks the pages of the specified relation to see if they are valid
-        enough to safely be loaded into the server's shared buffers.  If
-        given, <parameter>fork</parameter> specifies that only the pages of
-        the given fork are to be verified.  <parameter>fork</parameter> can
-        be <literal>main</literal> for the main data
-        fork, <literal>fsm</literal> for the free space
-        map, <literal>vm</literal> for the visibility map,
-        or <literal>init</literal> for the initialization fork.  The
-        default of <literal>NULL</literal> means that all forks of the
-        relation should be checked.  The function returns a list of block
-        numbers that appear corrupted along with the path names of their
-        files.  Use of this function is restricted to superusers by
-        default, but access may be granted to others
-        using <command>GRANT</command>.
-       </para></entry>
-      </row>
-     </tbody>
-    </tgroup>
-   </table>
-
-  </sect2>
-
   </sect1>
 
   <sect1 id="functions-trigger">