Update copyright dates with scripts/update-copyrights

I used these shell commands:

../glibc/scripts/update-copyrights $PWD/../gnulib/build-aux/update-copyright
(cd ../glibc && git commit -am"[this commit message]")

and then ignored the output, which consisted lines saying "FOO: warning:
copyright statement not found" for each of 6694 files FOO.
I then removed trailing white space from benchtests/bench-pthread-locks.c
and iconvdata/tst-iconv-big5-hkscs-to-2ucs4.c, to work around this
diagnostic from Savannah:
remote: *** pre-commit check failed ...
remote: *** error: lines with trailing whitespace found
remote: error: hook declined to update refs/heads/master

6 files changed, 6 insertions, 6 deletions

diff --git a/sysdeps/mach/i386/bits/mach/param.h b/sysdeps/mach/i386/bits/mach/param.h
index 80d6f9ff2c..e810f77a81 100644
--- a/sysdeps/mach/i386/bits/mach/param.h
+++ b/sysdeps/mach/i386/bits/mach/param.h
@@ -1,5 +1,5 @@
 /* Old-style Unix parameters and limits.  i386 Mach version.
-   Copyright (C) 1993-2020 Free Software Foundation, Inc.
+   Copyright (C) 1993-2021 Free Software Foundation, Inc.
    This file is part of the GNU C Library.
 
    The GNU C Library is free software; you can redistribute it and/or
diff --git a/sysdeps/mach/i386/machine-lock.h b/sysdeps/mach/i386/machine-lock.h
index a127475fe3..ea0f878a1a 100644
--- a/sysdeps/mach/i386/machine-lock.h
+++ b/sysdeps/mach/i386/machine-lock.h
@@ -1,5 +1,5 @@
 /* Machine-specific definition for spin locks.  i386 version.
-   Copyright (C) 1994-2020 Free Software Foundation, Inc.
+   Copyright (C) 1994-2021 Free Software Foundation, Inc.
    This file is part of the GNU C Library.
 
    The GNU C Library is free software; you can redistribute it and/or
diff --git a/sysdeps/mach/i386/machine-sp.h b/sysdeps/mach/i386/machine-sp.h
index 749d5f1d9b..280f3b7a4d 100644
--- a/sysdeps/mach/i386/machine-sp.h
+++ b/sysdeps/mach/i386/machine-sp.h
@@ -1,5 +1,5 @@
 /* Machine-specific function to return the stack pointer.  i386 version.
-   Copyright (C) 1994-2020 Free Software Foundation, Inc.
+   Copyright (C) 1994-2021 Free Software Foundation, Inc.
    This file is part of the GNU C Library.
 
    The GNU C Library is free software; you can redistribute it and/or
diff --git a/sysdeps/mach/i386/syscall.S b/sysdeps/mach/i386/syscall.S
index 1e9348f4c2..6f2e6b38bc 100644
--- a/sysdeps/mach/i386/syscall.S
+++ b/sysdeps/mach/i386/syscall.S
@@ -1,4 +1,4 @@
-/* Copyright (C) 1993-2020 Free Software Foundation, Inc.
+/* Copyright (C) 1993-2021 Free Software Foundation, Inc.
    This file is part of the GNU C Library.
 
    The GNU C Library is free software; you can redistribute it and/or
diff --git a/sysdeps/mach/i386/sysdep.h b/sysdeps/mach/i386/sysdep.h
index c132b3a4c3..5523a8b5f2 100644
--- a/sysdeps/mach/i386/sysdep.h
+++ b/sysdeps/mach/i386/sysdep.h
@@ -1,4 +1,4 @@
-/* Copyright (C) 1991-2020 Free Software Foundation, Inc.
+/* Copyright (C) 1991-2021 Free Software Foundation, Inc.
 
    This file is part of the GNU C Library.
 
diff --git a/sysdeps/mach/i386/thread_state.h b/sysdeps/mach/i386/thread_state.h
index 4579149c7e..022b19d04b 100644
--- a/sysdeps/mach/i386/thread_state.h
+++ b/sysdeps/mach/i386/thread_state.h
@@ -1,5 +1,5 @@
 /* Mach thread state definitions for machine-independent code.  i386 version.
-   Copyright (C) 1994-2020 Free Software Foundation, Inc.
+   Copyright (C) 1994-2021 Free Software Foundation, Inc.
    This file is part of the GNU C Library.
 
    The GNU C Library is free software; you can redistribute it and/or