patch 8.2.2015: Vim9: literal dict #{} is not like any other language

Problem:    Vim9: literal dict #{} is not like any other language.
Solution:   Support the JavaScript syntax.
diff --git a/src/testdir/test_vim9_func.vim b/src/testdir/test_vim9_func.vim
index e11564f..8d67b6f 100644
--- a/src/testdir/test_vim9_func.vim
+++ b/src/testdir/test_vim9_func.vim
@@ -1569,7 +1569,7 @@
 def TreeWalk(dir: string): list<any>
   return readdir(dir)->map({_, val ->
             fnamemodify(dir .. '/' .. val, ':p')->isdirectory()
-               ? {val: TreeWalk(dir .. '/' .. val)}
+               ? {[val]: TreeWalk(dir .. '/' .. val)}
                : val
              })
 enddef