Index: libcxxabi/src/demangle/cp-to-llvm.sh
===================================================================
--- libcxxabi/src/demangle/cp-to-llvm.sh
+++ libcxxabi/src/demangle/cp-to-llvm.sh
@@ -26,10 +26,8 @@
     chmod -w $LLVM_DEMANGLE_DIR/README.txt
     for I in $HDRS ; do
 	rm -f $LLVM_DEMANGLE_DIR/$I
-	cat - $I >$LLVM_DEMANGLE_DIR/$I <<EOF
-// Do not edit! -*- read-only -*-
-// See README.txt for instructions
-EOF
+	sed '1s|//=*-* .*\.h .*|//=== Do not edit! See README.txt. -*- mode:c++; eval:(read-only-mode) -*- ===//|' \
+	    $I >$LLVM_DEMANGLE_DIR/$I
 	chmod -w $LLVM_DEMANGLE_DIR/$I
     done
 fi
Index: llvm/include/llvm/Demangle/ItaniumDemangle.h
===================================================================
--- llvm/include/llvm/Demangle/ItaniumDemangle.h
+++ llvm/include/llvm/Demangle/ItaniumDemangle.h
@@ -1,6 +1,4 @@
-// Do not edit! -*- read-only -*-
-// See README.txt for instructions
-//===------------------------- ItaniumDemangle.h ----------------*- C++ -*-===//
+//=== Do not edit! See README.txt. -*- mode:c++; eval:(read-only-mode) -*- ===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
Index: llvm/include/llvm/Demangle/StringView.h
===================================================================
--- llvm/include/llvm/Demangle/StringView.h
+++ llvm/include/llvm/Demangle/StringView.h
@@ -1,6 +1,4 @@
-// Do not edit! -*- read-only -*-
-// See README.txt for instructions
-//===--- StringView.h -------------------------------------------*- C++ -*-===//
+//=== Do not edit! See README.txt. -*- mode:c++; eval:(read-only-mode) -*- ===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
Index: llvm/include/llvm/Demangle/Utility.h
===================================================================
--- llvm/include/llvm/Demangle/Utility.h
+++ llvm/include/llvm/Demangle/Utility.h
@@ -1,6 +1,4 @@
-// Do not edit! -*- read-only -*-
-// See README.txt for instructions
-//===--- Utility.h ----------------------------------------------*- C++ -*-===//
+//=== Do not edit! See README.txt. -*- mode:c++; eval:(read-only-mode) -*- ===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.