Update for automake 1.16.3.

Makefile.in

@@ -1,4 +1,4 @@
-# Makefile.in generated by automake 1.16.2 from Makefile.am.
+# Makefile.in generated by automake 1.16.3 from Makefile.am.
 # @configure_input@
 
 # Copyright (C) 1994-2020 Free Software Foundation, Inc.
@@ -284,6 +284,8 @@ am__post_remove_distdir = $(am__remove_distdir)
 DIST_ARCHIVES = $(distdir).tar.gz
 GZIP_ENV = --best
 DIST_TARGETS = dist-gzip
+# Exists only to be overridden by the user if desired.
+AM_DISTCHECK_DVI_TARGET = dvi
 distuninstallcheck_listfiles = find . -type f -print
 am__distuninstallcheck_listfiles = $(distuninstallcheck_listfiles) \
   | sed 's|^\./|$(prefix)/|' | grep -v '$(infodir)/dir$$'
@@ -1244,7 +1246,7 @@ distcheck: dist
 	    $(DISTCHECK_CONFIGURE_FLAGS) \
 	    --srcdir=../.. --prefix="$$dc_install_base" \
 	  && $(MAKE) $(AM_MAKEFLAGS) \
-	  && $(MAKE) $(AM_MAKEFLAGS) dvi \
+	  && $(MAKE) $(AM_MAKEFLAGS) $(AM_DISTCHECK_DVI_TARGET) \
 	  && $(MAKE) $(AM_MAKEFLAGS) check \
 	  && $(MAKE) $(AM_MAKEFLAGS) install \
 	  && $(MAKE) $(AM_MAKEFLAGS) installcheck \
@@ -1305,7 +1307,8 @@ installdirs:
 	done
 install: $(BUILT_SOURCES)
 	$(MAKE) $(AM_MAKEFLAGS) install-am
-install-exec: install-exec-am
+install-exec: $(BUILT_SOURCES)
+	$(MAKE) $(AM_MAKEFLAGS) install-exec-am
 install-data: install-data-am
 uninstall: uninstall-am
 
@@ -1468,7 +1471,7 @@ uninstall-am: uninstall-binPROGRAMS uninstall-man
 
 uninstall-man: uninstall-man1
 
-.MAKE: all check install install-am install-strip
+.MAKE: all check install install-am install-exec install-strip
 
 .PHONY: CTAGS GTAGS TAGS all all-am am--depfiles am--refresh check \
 	check-am clean clean-binPROGRAMS clean-cscope clean-generic \

configure

@@ -2449,12 +2449,7 @@ program_transform_name=`$as_echo "$program_transform_name" | sed "$ac_script"`
 am_aux_dir=`cd "$ac_aux_dir" && pwd`
 
 if test x"${MISSING+set}" != xset; then
-  case $am_aux_dir in
-  *\ * | *\	*)
-    MISSING="\${SHELL} \"$am_aux_dir/missing\"" ;;
-  *)
-    MISSING="\${SHELL} $am_aux_dir/missing" ;;
-  esac
+  MISSING="\${SHELL} '$am_aux_dir/missing'"
 fi
 # Use eval to expand $SHELL
 if eval "$MISSING --is-lightweight"; then