tests: add ftruncate64.test and truncate64.test

* tests/ftruncate64.c: New file.
* tests/truncate64.c: Likewise.
* tests/ftruncate64.test: New test.
* tests/truncate64.test: Likewise.
* tests/Makefile.am (check_PROGRAMS): Add ftruncate64 and truncate64.
(ftruncate64_CFLAGS, truncate64_CFLAGS): Define.
(TESTS): Add ftruncate64.test and truncate64.test.
* tests/.gitignore: Add ftruncate64 and truncate64.
diff --git a/tests/ftruncate64.test b/tests/ftruncate64.test
new file mode 100755
index 0000000..43cd9ad
--- /dev/null
+++ b/tests/ftruncate64.test
@@ -0,0 +1,13 @@
+#!/bin/sh
+
+# Check ftruncate64 syscall decoding.
+
+. "${srcdir=.}/init.sh"
+
+run_prog > /dev/null
+OUT="$LOG.out"
+run_strace -a36 -eftruncate64 $args > "$OUT"
+match_diff "$LOG" "$OUT"
+rm -f "$OUT"
+
+exit 0