* doc/autoconf.texi: Add some syntax highlighting helper comments.

Index: doc/autoconf.texi
===================================================================
RCS file: /cvsroot/autoconf/autoconf/doc/autoconf.texi,v
retrieving revision 1.897
diff -u -r1.897 autoconf.texi
--- doc/autoconf.texi	10 May 2005 23:37:37 -0000	1.897
+++ doc/autoconf.texi	15 May 2005 03:18:09 -0000
@@ -8554,6 +8554,7 @@
 
 @table @samp
 @item $$
address@hidden syntax highlighting help: $$
 The character @samp{$}.
 
 @item $f
@@ -11961,6 +11963,7 @@
   test -n "$tmp" && test -d "$tmp"
 @} || @{
   tmp=$TMPDIR/foo$$-$RANDOM
address@hidden syntax highlighting help: $$
   (umask 077 && mkdir "$tmp")
 @} || exit $?
 @end example
@@ -12617,6 +12620,7 @@
         for i in $(HEADERS); do \
           $(INSTALL) -m 644 `test -f $$i || echo ../pkg/src/`$$i \
             $(DESTDIR)$(includedir)/$$i; \
address@hidden syntax highlighting help: $$
         done
 @end example
 
@@ -12677,6 +12681,7 @@
           i=`expr "$$i" : '../pkg/src/\(.*\)'`;
           $(INSTALL) -m 644 `test -f $$i || echo ../pkg/src/`$$i \
             $(DESTDIR)$(includedir)/$$i; \
address@hidden syntax highlighting help: $$
         done
 @end example