build: Use Test::Harness instead of ExtUtils::Command::MM

This stops using the "internal use only" module ExtUtils::Command::MM,
and preserves the order of the modules as passed on the command line,
which allows us to remove the sequence number prefixes.

Makecheck.am

@@ -17,9 +17,10 @@ check-local: $(test_data) $(test_cases)
 	PATH="$(top_builddir)/src:$(top_builddir)/scripts:$(top_builddir)/utils:$(PATH)" \
 	  LC_ALL=C \
 	  $(TEST_ENV_VARS) \
+	  HARNESS_VERBOSE=$(TEST_VERBOSE) \
 	  srcdir=$(srcdir) builddir=$(builddir) \
 	  PERL5LIB=$(top_srcdir)/scripts PERL_DL_NONLAZY=1 \
 	  PERL5OPT=$(TEST_COVERAGE) \
 	  $(PERL) -I$(top_srcdir)/scripts \
-	    -MExtUtils::Command::MM -e "test_harness($(TEST_VERBOSE), '.')" \
+	    -MTest::Harness -e 'Test::Harness::runtests(@ARGV)' \
 	    $(addprefix $(srcdir)/,$(test_cases))

debian/changelog

@@ -13,6 +13,8 @@ dpkg (1.17.7) UNRELEASED; urgency=low
   * Use exit instead of return to exit a subshell in dpkg-maintscript-helper.
     Thanks to Richard Levitte <richard@levitte.org>. Closes: #738957
   * Localize $_ in Perl functions with while (<$fh>) style loops.
+  * Perl test suite cleanup:
+    - Switch test suite runner from ExtUtils::Command::MM to Test::Harness.
 
   [ Updated dpkg translations ]
   * German (Sven Joachim).