test/old: stub CanRunVimInTerminal()

src/nvim/testdir/runtest.vim

@@ -67,7 +67,7 @@ lang mess C
 let v:testing = 1
 
 " Support function: get the alloc ID by name.
-function GetAllocId(name)
+func GetAllocId(name)
   exe 'split ' . s:srcdir . '/alloc.h'
   let top = search('typedef enum')
   if top == 0
@@ -81,6 +81,11 @@ function GetAllocId(name)
   return lnum - top - 1
 endfunc
 
+func CanRunVimInTerminal()
+  " Nvim: always false, we use Lua screen-tests instead.
+  return 0
+endfunc
+
 func RunTheTest(test)
   echo 'Executing ' . a:test