vim-patch:9.0.0406: deferred functions not invoked when partial func exits

Problem:    Deferred functions not invoked when partial func exits.
Solution:   Create a funccall_T when calling a :def function.

9667b2c888

The remove_funccal() function is currently unused, but it will be used
in patch 9.0.0618.

Co-authored-by: Bram Moolenaar <Bram@vim.org>

test/old/testdir/test_user_func.vim

@@ -633,5 +633,34 @@ func Test_defer_quitall()
   call assert_false(filereadable('XQuitallTwo'))
 endfunc
 
+func Test_defer_quitall_in_expr_func()
+  throw 'Skipped: Vim9 script is N/A'
+  let lines =<< trim END
+      def DefIndex(idx: number, val: string): bool
+        call writefile([idx .. ': ' .. val], 'Xentry' .. idx, 'D')
+        if val == 'b'
+          qa!
+        endif
+        return val == 'c'
+      enddef
+
+      def Test_defer_in_funcref()
+        assert_equal(2, indexof(['a', 'b', 'c'], funcref('g:DefIndex')))
+      enddef
+      call Test_defer_in_funcref()
+  END
+  call writefile(lines, 'XdeferQuitallExpr', 'D')
+  let res = system(GetVimCommandClean() .. ' -X -S XdeferQuitallExpr')
+  call assert_equal(0, v:shell_error)
+  call assert_false(filereadable('Xentry0'))
+  call assert_false(filereadable('Xentry1'))
+  call assert_false(filereadable('Xentry2'))
+endfunc
+
+func FuncIndex(idx, val)
+  call writefile([a:idx .. ': ' .. a:val], 'Xentry' .. a:idx, 'D')
+  return a:val == 'c'
+endfunc
+
 
 " vim: shiftwidth=2 sts=2 expandtab