refactor: Remove VimL function test()

vim-patch:7.4.1838

runtime/doc/vim_diff.txt

@@ -77,12 +77,15 @@ Clipboard integration		|provider-clipboard|
 
 USER EXPERIENCE  ~
 
-A major goal of Nvim is to work intuitively and consistently. For example,
-Nvim does not have `-X`, a platform-specific option available in some Vim
-builds (with potential surprises: http://stackoverflow.com/q/14635295). Nvim
-avoids features that cannot be provided on all platforms--instead that is
-delegated to external plugins/extensions.
+Working intuitively and consistently is a major goal of Nvim. Examples:
 
+- Nvim does not have `-X`, a platform-specific option "sometimes" available in
+  Vim (with potential surprises: http://stackoverflow.com/q/14635295). Nvim
+  avoids features that cannot be provided on all platforms--instead that is
+  delegated to external plugins/extensions.
+
+- Test-only globals and functions such as test_autochdir(), test_settime(),
+  etc., are not exposed (because they don't exist).
 
 ARCHITECTURE ~
 
@@ -271,6 +274,19 @@ MS-DOS support:
 Highlight groups:
   |hl-VisualNOS|
 
+Test functions:
+  test_alloc_fail()
+  test_autochdir()
+  test_disable_char_avail()
+  test_garbagecollect_now()
+  test_null_channel()
+  test_null_dict()
+  test_null_job()
+  test_null_list()
+  test_null_partial()
+  test_null_string()
+  test_settime()
+
 Other options:
   'antialias'
   'cpoptions' ("g", "w", "H", "*", "-", "j", and all POSIX flags were removed)

src/nvim/eval.c

@@ -17249,14 +17249,6 @@ static void f_termopen(typval_T *argvars, typval_T *rettv, FunPtr fptr)
   return;
 }
 
-/*
- * "test(list)" function: Just checking the walls...
- */
-static void f_test(typval_T *argvars, typval_T *rettv, FunPtr fptr)
-{
-  /* Used for unit testing.  Change the code below to your liking. */
-}
-
 static bool callback_from_typval(Callback *callback, typval_T *arg)
 {
   if (arg->v_type == VAR_PARTIAL && arg->vval.v_partial != NULL) {

src/nvim/eval.lua

@@ -302,7 +302,6 @@ return {
     tanh={args=1, func="float_op_wrapper", data="&tanh"},
     tempname={},
     termopen={args={1, 2}},
-    test={args=1},
     timer_start={args={2,3}},
     timer_stop={args=1},
     tolower={args=1},

src/nvim/version.c

@@ -602,7 +602,7 @@ static int included_patches[] = {
   1841,
   1840,
   // 1839,
-  // 1838,
+  1838,
   1837,
   1836,
   1835,