Try to eliminate more Windows build warnings.

test-corpus.sh

@@ -0,0 +1,22 @@
+#!/bin/sh
+#
+# Script to test PDFio against a directory of PDF files.
+#
+# Copyright © 2025 by Michael R Sweet.
+#
+# Licensed under Apache License v2.0.  See the file "LICENSE" for more
+# information.
+#
+# Usage:
+#
+#   ./test-corpus.sh DIRECTORY
+#
+
+if test $# = 1; then
+    echo "Usage: ./test-corpus.sh DIRECTORY"
+    exit 1
+fi
+
+for file in $(find "$@" -name \*.pdf -print); do
+    ./testpdfio $file 2>$file.log || echo $file
+done