Update copyrights for 2020

Backpatch-through: update all files in master, backpatch legal files through 9.4

src/backend/access/common/attmap.c

@@ -10,7 +10,7 @@
  * columns in a different order, taking into account dropped columns.
  * They are also used by the tuple conversion routines in tupconvert.c.
  *
- * Portions Copyright (c) 1996-2019, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  *

src/backend/access/common/bufmask.c

@@ -5,7 +5,7 @@
  *	  in a page which can be different when the WAL is generated
  *	  and when the WAL is applied.
  *
- * Portions Copyright (c) 2016-2019, PostgreSQL Global Development Group
+ * Portions Copyright (c) 2016-2020, PostgreSQL Global Development Group
  *
  * Contains common routines required for masking a page.
  *

src/backend/access/common/detoast.c

@@ -3,7 +3,7 @@
  * detoast.c
  *	  Retrieve compressed or external variable size attributes.
  *
- * Copyright (c) 2000-2019, PostgreSQL Global Development Group
+ * Copyright (c) 2000-2020, PostgreSQL Global Development Group
  *
  * IDENTIFICATION
  *	  src/backend/access/common/detoast.c

src/backend/access/common/heaptuple.c

@@ -45,7 +45,7 @@
  * and we'd like to still refer to them via C struct offsets.
  *
  *
- * Portions Copyright (c) 1996-2019, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  *

src/backend/access/common/indextuple.c

@@ -4,7 +4,7 @@
  *	   This file contains index tuple accessor and mutator routines,
  *	   as well as various tuple utilities.
  *
- * Portions Copyright (c) 1996-2019, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  *

src/backend/access/common/printsimple.c

@@ -8,7 +8,7 @@
  *	  doesn't handle standalone backends or protocol versions other than
  *	  3.0, because we don't need such handling for current applications.
  *
- * Portions Copyright (c) 1996-2019, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  * IDENTIFICATION

src/backend/access/common/printtup.c

@@ -5,7 +5,7 @@
  *	  clients and standalone backends are supported here).
  *
  *
- * Portions Copyright (c) 1996-2019, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  * IDENTIFICATION

src/backend/access/common/relation.c

@@ -3,7 +3,7 @@
  * relation.c
  *	  Generic relation related routines.
  *
- * Portions Copyright (c) 1996-2019, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  *

src/backend/access/common/reloptions.c

@@ -3,7 +3,7 @@
  * reloptions.c
  *	  Core support for relation options (pg_class.reloptions)
  *
- * Portions Copyright (c) 1996-2019, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  *

src/backend/access/common/scankey.c

@@ -3,7 +3,7 @@
  * scankey.c
  *	  scan key support code
  *
- * Portions Copyright (c) 1996-2019, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  *

src/backend/access/common/session.c

@@ -12,7 +12,7 @@
  * Currently this infrastructure is used to share:
  * - typemod registry for ephemeral row-types, i.e. BlessTupleDesc etc.
  *
- * Portions Copyright (c) 2017-2019, PostgreSQL Global Development Group
+ * Portions Copyright (c) 2017-2020, PostgreSQL Global Development Group
  *
  * src/backend/access/common/session.c
  *

src/backend/access/common/toast_internals.c

@@ -3,7 +3,7 @@
  * toast_internals.c
  *	  Functions for internal use by the TOAST system.
  *
- * Copyright (c) 2000-2019, PostgreSQL Global Development Group
+ * Copyright (c) 2000-2020, PostgreSQL Global Development Group
  *
  * IDENTIFICATION
  *	  src/backend/access/common/toast_internals.c

src/backend/access/common/tupconvert.c

@@ -7,7 +7,7 @@
  * equivalent but might have columns in a different order or different sets of
  * dropped columns.
  *
- * Portions Copyright (c) 1996-2019, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  *

src/backend/access/common/tupdesc.c

@@ -3,7 +3,7 @@
  * tupdesc.c
  *	  POSTGRES tuple descriptor support code
  *
- * Portions Copyright (c) 1996-2019, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  *