tests: more syntax-checks

* gnulib: update to latest
* cfg.mk (sc_prohibit_empty_lines_at_EOF): Remove, now that it's
in gnulib's maint.mk.
(_hv_file): Override the default.

cfg.mk

@@ -32,6 +32,9 @@ old_NEWS_hash = 9518f4930d702a9fa6ac6b9fd06cca94
 # Add an exemption for sc_makefile_at_at_check.
 _makefile_at_at_check_exceptions = ' && !/^cu_install_program =/'
 
+# Our help-version script is in a slightly different location.
+_hv_file ?= $(srcdir)/tests/misc/help-version
+
 # Ensure that the list of O_ symbols used to compute O_FULLBLOCK is complete.
 dd = $(srcdir)/src/dd.c
 sc_dd_O_FLAGS:
@@ -315,30 +318,6 @@ sc_space_before_open_paren:
 	else :;								\
 	fi
 
-# The following tail+perl pipeline would be much more concise, and would
-# produce slightly better output (including counts) if written as
-#   perl -ln -0777 -e '/\n(\n+)$/ and print "$ARGV: ".length $1' ...
-# but that would be far less efficient, reading the entire contents
-# of each file, rather than just the last few bytes of each.
-#
-# This is a perl script that operates on the output of
-# tail -n1 TWO_OR_MORE_FILES
-# Print the name of each file that ends in two or more newline bytes.
-# Exit nonzero if at least one such file is found, otherwise, exit 0.
-#
-# Use this if you want to remove trailing empty lines from selected files:
-#   perl -pi -0777 -e 's/\n\n+$/\n/' files...
-#
-detect_empty_lines_at_EOF_ =						\
-  /^==> ([^\n]+) <==\n\n/m and (print "$$1\n"), $$fail = 1;		\
-  END { exit defined $$fail }
-
-sc_prohibit_empty_lines_at_EOF:
-	@tail -n1 $$($(VC_LIST_EXCEPT)) /dev/null			\
-	    | perl -00 -ne '$(detect_empty_lines_at_EOF_)'		\
-	  || { echo '$(ME): the above files end with empty line(s)'	\
-		1>&2; exit 1; } || :;					\
-
 include $(srcdir)/dist-check.mk
 
 update-copyright-env = \