build-sys: fix crlf-ending C code

On msys2, the shader-to-C script produces bad C:
./ui/shader/texture-blit-vert.h:2:5: error: missing terminating " character [-Werror]

Fix it by changing the line ending from crlf to lf, and convert the
script to Python (qemu build seems perl-free after that).

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Acked-by: Thomas Huth <thuth@redhat.com>
Message-Id: <20230110132700.833690-2-marcandre.lureau@redhat.com>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20230124180127.1881110-6-alex.bennee@linaro.org>
(cherry picked from commit e2c4012bc3)
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>

scripts/shaderinclude.py

@@ -0,0 +1,26 @@
+#!/usr/bin/env python3
+#
+# Copyright (C) 2023 Red Hat, Inc.
+#
+# SPDX-License-Identifier: GPL-2.0-or-later
+
+import sys
+import os
+
+
+def main(args):
+    file_path = args[1]
+    basename = os.path.basename(file_path)
+    varname = basename.replace('-', '_').replace('.', '_')
+
+    with os.fdopen(sys.stdout.fileno(), "wt", closefd=False, newline='\n') as stdout:
+        with open(file_path, "r", encoding='utf-8') as file:
+            print(f'static GLchar {varname}_src[] =', file=stdout)
+            for line in file:
+                line = line.rstrip()
+                print(f'    "{line}\\n"', file=stdout)
+            print('    "\\n";', file=stdout)
+
+
+if __name__ == '__main__':
+    sys.exit(main(sys.argv))