Merge branch 'hn/reftable-coverity-fixes'

Problems identified by Coverity in the reftable code have been
corrected.

* hn/reftable-coverity-fixes:
  reftable: add print functions to the record types
  reftable: make reftable_record a tagged union
  reftable: remove outdated file reftable.c
  reftable: implement record equality generically
  reftable: make reftable-record.h function signatures const correct
  reftable: handle null refnames in reftable_ref_record_equal
  reftable: drop stray printf in readwrite_test
  reftable: order unittests by complexity
  reftable: all xxx_free() functions accept NULL arguments
  reftable: fix resource warning
  reftable: ignore remove() return value in stack_test.c
  reftable: check reftable_stack_auto_compact() return value
  reftable: fix resource leak blocksource.c
  reftable: fix resource leak in block.c error path
  reftable: fix OOB stack write in print functions

t/helper/test-reftable.c

@@ -3,15 +3,16 @@
 
 int cmd__reftable(int argc, const char **argv)
 {
+	/* test from simple to complex. */
 	basics_test_main(argc, argv);
-	block_test_main(argc, argv);
-	merged_test_main(argc, argv);
-	pq_test_main(argc, argv);
 	record_test_main(argc, argv);
-	refname_test_main(argc, argv);
-	readwrite_test_main(argc, argv);
-	stack_test_main(argc, argv);
+	block_test_main(argc, argv);
 	tree_test_main(argc, argv);
+	pq_test_main(argc, argv);
+	readwrite_test_main(argc, argv);
+	merged_test_main(argc, argv);
+	stack_test_main(argc, argv);
+	refname_test_main(argc, argv);
 	return 0;
 }