Update copyright for 2021

Backpatch-through: 9.5

src/backend/access/spgist/spgdoinsert.c

@@ -4,7 +4,7 @@
  *	  implementation of insert algorithm
  *
  *
- * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1996-2021, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  * IDENTIFICATION

src/backend/access/spgist/spginsert.c

@@ -5,7 +5,7 @@
  *
  * All the actual insertion logic is in spgdoinsert.c.
  *
- * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1996-2021, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  * IDENTIFICATION

src/backend/access/spgist/spgkdtreeproc.c

@@ -4,7 +4,7 @@
  *	  implementation of k-d tree over points for SP-GiST
  *
  *
- * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1996-2021, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  * IDENTIFICATION

src/backend/access/spgist/spgproc.c

@@ -4,7 +4,7 @@
  *	  Common supporting procedures for SP-GiST opclasses.
  *
  *
- * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1996-2021, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  * IDENTIFICATION

src/backend/access/spgist/spgquadtreeproc.c

@@ -4,7 +4,7 @@
  *	  implementation of quad tree over points for SP-GiST
  *
  *
- * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1996-2021, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  * IDENTIFICATION

src/backend/access/spgist/spgscan.c

@@ -4,7 +4,7 @@
  *	  routines for scanning SP-GiST indexes
  *
  *
- * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1996-2021, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  * IDENTIFICATION

src/backend/access/spgist/spgtextproc.c

@@ -29,7 +29,7 @@
  * No new entries ever get pushed into a -2-labeled child, either.
  *
  *
- * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1996-2021, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  * IDENTIFICATION

src/backend/access/spgist/spgutils.c

@@ -4,7 +4,7 @@
  *	  various support functions for SP-GiST
  *
  *
- * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1996-2021, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  * IDENTIFICATION

src/backend/access/spgist/spgvacuum.c

@@ -4,7 +4,7 @@
  *	  vacuum for SP-GiST
  *
  *
- * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1996-2021, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  * IDENTIFICATION

src/backend/access/spgist/spgvalidate.c

@@ -3,7 +3,7 @@
  * spgvalidate.c
  *	  Opclass validator for SP-GiST.
  *
- * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1996-2021, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  * IDENTIFICATION

src/backend/access/spgist/spgxlog.c

@@ -4,7 +4,7 @@
  *	  WAL replay logic for SP-GiST
  *
  *
- * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1996-2021, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  * IDENTIFICATION