Port "$@" to OpenIndiana ksh93

In http://lists.gnu.org/archive/html/bug-autoconf/2015-12/msg00000.html
Pavel Raiskup reports that ${1+"$@"} runs afoul of a bug in /bin/sh
(derived from ksh 93t+ 2010-03-05).  ${1+"$@"} works around an ancient
bug in long-dead shells, so remove the workaround.
* admin/check-doc-strings, configure.ac, lib-src/rcs2log:
Use plain "$@" rather than ${1+"$@"}.

admin/check-doc-strings

@@ -1,5 +1,5 @@
 : #-*- Perl -*-
-eval 'exec perl -S $0 ${1+"$@"}' # Portability kludge
+eval 'exec perl -S $0 "$@"' # Portability kludge
     if 0;
 
 # Author: Martin Buchholz
@@ -299,4 +299,3 @@ foreach my $fun (sort keys %texi_funtype) {
     print "nuke-this-doc: $fun $texi_funtype{$fun}\n";
   }
 }
-

configure.ac

@@ -33,7 +33,7 @@ emacs_config_options=
 optsep=
 dnl This is the documented way to record the args passed to configure,
 dnl rather than $ac_configure_args.
-for opt in ${1+"$@"} CFLAGS CPPFLAGS LDFLAGS; do
+for opt in "$@" CFLAGS CPPFLAGS LDFLAGS; do
   case $opt in
     -n | --no-create | --no-recursion)
       continue ;;

lib-src/rcs2log

@@ -403,8 +403,8 @@ case $rlogfile in
 	esac
 
 	case $datearg in
-	?*) $rlog $rlog_options "$datearg" ${1+"$@"} >$rlogfile;;
+	?*) $rlog $rlog_options "$datearg" "$@" >$rlogfile;;
-	'') $rlog $rlog_options ${1+"$@"} >$rlogfile;;
+	'') $rlog $rlog_options "$@" >$rlogfile;;
 	esac || exit;;
 esac