patch 8.1.0780: terminal test fails on Mac

Problem:    Terminal test fails on Mac.
Solution:   Skip the test on Mac.
diff --git a/src/testdir/test_terminal.vim b/src/testdir/test_terminal.vim
index 0e0c76c..f78d66c 100644
--- a/src/testdir/test_terminal.vim
+++ b/src/testdir/test_terminal.vim
@@ -643,8 +643,9 @@
 endfunc
 
 func Test_terminal_no_cmd()
+  " Does not work on Mac.
   " Todo: make this work on Win32 again
-  if has('win32')
+  if has('mac') || has('win32')
     return
   endif
   let buf = term_start('NONE', {})