Prepare version 1.6.1

Pick up some fixes for issues that were detected while porting lld.

lzsabi.tex

@@ -1,4 +1,4 @@
-% © Copyright IBM Corporation 2001, 2021
+% © Copyright IBM Corporation 2001, 2024
 % © Copyright Linux Foundation 2002
 %
 % SPDX-License-Identifier: GFDL-1.1-no-invariants-only
@@ -15,7 +15,7 @@
 
 % --- Version ---
 
-\newcommand{\Version}{1.6}
+\newcommand{\Version}{1.6.1}
 
 % --- Packages ---
 
@@ -321,7 +321,7 @@
 
   \noindent Version \Version
 
-  \noindent © Copyright IBM Corporation 2001, 2021
+  \noindent © Copyright IBM Corporation 2001, 2024
 
   \noindent © Copyright Linux Foundation 2002
 
@@ -354,6 +354,8 @@ \chapter*{About This Book}
 \section*{History}
 
 \begin{description}
+\item[1.6.1] Minor release to pick up a few fixes.  Published at
+  \url{https://github.com/ibm/s390x-abi}, January 2024.
 \item[1.6] Describe vector types and registers (based on input from
   Andreas Krebbel); mention condition code and program mask; enhance
   exception handling information.  Published at