Merge topic 'depfile-transform-escapes' into release-4.4

2253c1d7c7 cmTransformDepfile: Fix processing filenames with `$` and `#` in them

Acked-by: Kitware Robot <kwrobot@kitware.com>
Merge-request: !12142

Source/cmTransformDepfile.cxx

@@ -26,6 +26,12 @@ void WriteFilenameGcc(cmsys::ofstream& fout, std::string const& filename)
 {
   for (auto c : filename) {
     switch (c) {
+      case '$':
+        fout << "$$";
+        break;
+      case '#':
+        fout << "\\#";
+        break;
       case ' ':
         fout << "\\ ";
         break;