patch 8.2.0207: crash when missing member type on list argument

Problem:    Crash when missing member type on list argument.
Solution:   Check for invalid type. (closes #5572)
diff --git a/src/testdir/test_vim9_script.vim b/src/testdir/test_vim9_script.vim
index fee0708..dc1c0b9 100644
--- a/src/testdir/test_vim9_script.vim
+++ b/src/testdir/test_vim9_script.vim
@@ -160,13 +160,16 @@
 enddef
 
 def Test_return_type_wrong()
-  " TODO: why is ! needed for Mac and FreeBSD?
   CheckScriptFailure(['def Func(): number', 'return "a"', 'enddef'], 'expected number but got string')
   CheckScriptFailure(['def Func(): string', 'return 1', 'enddef'], 'expected string but got number')
   CheckScriptFailure(['def Func(): void', 'return "a"', 'enddef'], 'expected void but got string')
   CheckScriptFailure(['def Func()', 'return "a"', 'enddef'], 'expected void but got string')
 enddef
 
+def Test_arg_type_wrong()
+  CheckScriptFailure(['def Func3(items: list)', 'echo "a"', 'enddef'], 'E1008: Missing <type>')
+enddef
+
 def Test_try_catch()
   let l = []
   try