Move definition of standard collations from initdb to pg_collation.dat

The standard collations "ucs_basic" and "unicode" were defined in
initdb, even though pg_collation.dat seems like the correct place for
them.  It seems this was just forgotten during various reorganizations
of initdb and pg_collation.dat/.h over time.

Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://www.postgresql.org/message-id/flat/08b58ecd-0d50-9395-ed51-dc8294e3fd2b%40enterprisedb.com

src/bin/initdb/initdb.c

@@ -1695,20 +1695,7 @@ setup_description(FILE *cmdfd)
 static void
 setup_collation(FILE *cmdfd)
 {
-	/*
-	 * Add SQL-standard names.  We don't want to pin these, so they don't go
-	 * in pg_collation.dat.  But add them before reading system collations, so
-	 * that they win if libc defines a locale with the same name.
-	 */
-	PG_CMD_PRINTF("INSERT INTO pg_collation (oid, collname, collnamespace, collowner, collprovider, collisdeterministic, collencoding, colliculocale)"
-				  "VALUES (pg_nextoid('pg_catalog.pg_collation', 'oid', 'pg_catalog.pg_collation_oid_index'), 'unicode', 'pg_catalog'::regnamespace, %u, '%c', true, -1, 'und');\n\n",
-				  BOOTSTRAP_SUPERUSERID, COLLPROVIDER_ICU);
-
-	PG_CMD_PRINTF("INSERT INTO pg_collation (oid, collname, collnamespace, collowner, collprovider, collisdeterministic, collencoding, collcollate, collctype)"
-				  "VALUES (pg_nextoid('pg_catalog.pg_collation', 'oid', 'pg_catalog.pg_collation_oid_index'), 'ucs_basic', 'pg_catalog'::regnamespace, %u, '%c', true, %d, 'C', 'C');\n\n",
-				  BOOTSTRAP_SUPERUSERID, COLLPROVIDER_LIBC, PG_UTF8);
-
-	/* Now import all collations we can find in the operating system */
+	/* Import all collations we can find in the operating system */
 	PG_CMD_PUTS("SELECT pg_import_system_collations('pg_catalog');\n\n");
 }
 

src/include/catalog/catversion.h

@@ -57,6 +57,6 @@
  */
 
 /*							yyyymmddN */
-#define CATALOG_VERSION_NO	202303291
+#define CATALOG_VERSION_NO	202303292
 
 #endif

src/include/catalog/pg_collation.dat

@@ -23,5 +23,12 @@
   descr => 'standard POSIX collation',
   collname => 'POSIX', collprovider => 'c', collencoding => '-1',
   collcollate => 'POSIX', collctype => 'POSIX' },
+{ oid => '962', descr => 'sorts by Unicode code point',
+  collname => 'ucs_basic', collprovider => 'c', collencoding => '6',
+  collcollate => 'C', collctype => 'C' },
+{ oid => '963',
+  descr => 'sorts using the Unicode Collation Algorithm with default settings',
+  collname => 'unicode', collprovider => 'i', collencoding => '-1',
+  colliculocale => 'und' },
 
 ]