Add Feature testing for Windows binaries

* etc/w32-feature.el: New file

etc/w32-feature.el

@@ -0,0 +1,87 @@
+;;; w32-feature.el --- Check Availability of Emacs Features  -*- lexical-binding: t -*-
+
+;; Copyright (C) 2020 Free Software Foundation, Inc.
+
+;; Author: Phillip Lord <phillip.lord@russet.org.uk>
+
+;; This file is part of GNU Emacs.
+
+;; GNU Emacs is free software: you can redistribute it and/or modify
+;; it under the terms of the GNU General Public License as published by
+;; the Free Software Foundation, either version 3 of the License, or
+;; (at your option) any later version.
+
+;; GNU Emacs is distributed in the hope that it will be useful,
+;; but WITHOUT ANY WARRANTY; without even the implied warranty of
+;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+;; GNU General Public License for more details.
+
+;; You should have received a copy of the GNU General Public License
+;; along with GNU Emacs.  If not, see <https://www.gnu.org/licenses/>.
+
+;;; Commentary:
+
+;; This file provides tests for various features of Emacs. It is
+;; designed to check whether bundled binary distributions of Emacs on
+;; windows are fully functional.
+
+;;; Code:
+(require 'ert)
+
+(ert-deftest feature-optimization ()
+  (should
+   (string-match-p "CFLAGS=-O2" system-configuration-options)))
+
+(ert-deftest feature-harfbuzz ()
+  (should
+   (eq
+    'harfbuzz
+    (car (frame-parameter nil 'font-backend)))))
+
+(ert-deftest feature-gnutls ()
+  (should (gnutls-available-p)))
+
+(ert-deftest feature-zlib ()
+  (should (zlib-available-p)))
+
+(ert-deftest feature-thread ()
+  (should (fboundp 'make-thread)))
+
+(ert-deftest feature-json ()
+  (should
+   (fboundp 'json-serialize)))
+
+(ert-deftest feature-gmp ()
+  (should
+   (string-match-p "GMP" system-configuration-options)))
+
+(ert-deftest feature-module ()
+  (should (fboundp 'module-load)))
+
+(ert-deftest feature-libxml ()
+  (should (libxml-available-p)))
+
+(ert-deftest feature-lcms2 ()
+  (should (lcms2-available-p)))
+
+(ert-deftest feature-xpm ()
+  (should (image-type-available-p 'xpm)))
+
+(ert-deftest feature-gif ()
+  (should (image-type-available-p 'gif)))
+
+(ert-deftest feature-png ()
+  (should (image-type-available-p 'png)))
+
+(ert-deftest feature-xpm ()
+  (should (image-type-available-p 'xpm)))
+
+(ert-deftest feature-jpeg ()
+  (should (image-type-available-p 'jpeg)))
+
+(ert-deftest feature-tiff ()
+  (should (image-type-available-p 'tiff)))
+
+(ert-deftest feature-svg ()
+  (should (image-type-available-p 'svg)))
+;;; feature.el ends here