vim-patch:8.2.2176: crash with a sequence of fold commands

Problem:    Crash with a sequence of fold commands.
Solution:   Bail out when there are no folds at all.  Add a test (Dominique
            Pellé) (closes vim/vim#7515)
6a78f32844

N/A patches for version.c:

vim-patch:8.2.2174: Mac version doesn't specify the CPU architecture

Problem:    Mac version doesn't specify the CPU architecture.
Solution:   Add "arm64" or "x86_64". (Yee Cheng Chin, closes vim/vim#7519)
8c9d98a8af

vim-patch:8.2.2175: github actions: clang-11 handling suboptimal

Problem:    Github actions: clang-11 handling suboptimal.
Solution:   Separate step of installing clang-11. Get ubuntu release name
            dynamically. (Ozaki Kiichi, closes vim/vim#7514)
9aff970204

src/nvim/fold.c

@@ -902,8 +902,9 @@ int foldMoveTo(
     bool last = false;
     for (;; ) {
       if (!foldFind(gap, curwin->w_cursor.lnum - lnum_off, &fp)) {
-        if (!updown)
+        if (!updown || gap->ga_len == 0) {
           break;
+        }
 
         /* When moving up, consider a fold above the cursor; when
          * moving down consider a fold below the cursor. */