feat(lua): show proper verbose output for lua configuration

`:verbose` didn't work properly with lua configs (For example:
    options or keymaps are set from lua, just say that they were set
    from lua, doesn't say where they were set at.

This fixes that issue. Now `:verbose` will provide filename and line no
when option/keymap is set from lua.

Changes:
  - compiles lua/vim/keymap.lua as vim/keymap.lua
 - When souring a lua file current_sctx.sc_sid is set to SID_LUA
 - Moved finding scripts SID out of `do_source()` to `get_current_script_id()`.
   So it can be reused for lua files.
 - Added new function `nlua_get_sctx` that extracts current lua scripts
   name and line no with debug library. And creates a sctx for it.
     NOTE: This function ignores C functions and blacklist which
     currently contains only vim/_meta.lua so vim.o/opt wrappers aren't
     targeted.
 - Added function `nlua_set_sctx` that changes provided sctx to current
   lua scripts sctx if a lua file is being executed.
 - Added tests in tests/functional/lua/verbose_spec.lua
 - add primary support for additional types (:autocmd, :function, :syntax) to lua verbose
    Note: These can't yet be directly set from lua but once that's possible
    :verbose should work for them hopefully :D
 - add :verbose support for nvim_exec & nvim_command within lua
    Currently auto commands/commands/functions ... can only be defined
    by nvim_exec/nvim_command this adds support for them. Means if those
    Are defined within lua with vim.cmd/nvim_exec :verbose will show their
    location . Though note it'll show the line no on which nvim_exec call was made.

2 files changed, 161 insertions, 5 deletions

diff --git a/test/functional/api/keymap_spec.lua b/test/functional/api/keymap_spec.lua
index e49e0b8cc4..6562b40d53 100644
--- a/test/functional/api/keymap_spec.lua
+++ b/test/functional/api/keymap_spec.lua
@@ -15,6 +15,9 @@ local pcall_err = helpers.pcall_err
 local shallowcopy = helpers.shallowcopy
 local sleep = helpers.sleep
 
+local sid_api_client = -9
+local sid_lua = -8
+
 describe('nvim_get_keymap', function()
   before_each(clear)
 
@@ -340,7 +343,7 @@ describe('nvim_get_keymap', function()
       script=0,
       silent=0,
       expr=0,
-      sid=0,
+      sid=sid_lua,
       buffer=0,
       nowait=0,
       mode='n',
@@ -357,7 +360,7 @@ describe('nvim_get_keymap', function()
       script=0,
       silent=0,
       expr=0,
-      sid=0,
+      sid=sid_api_client,
       buffer=0,
       nowait=0,
       mode='n',
@@ -400,7 +403,7 @@ describe('nvim_set_keymap, nvim_del_keymap', function()
     to_return.silent = not opts.silent and 0 or 1
     to_return.nowait = not opts.nowait and 0 or 1
     to_return.expr = not opts.expr and 0 or 1
-    to_return.sid = not opts.sid and 0 or opts.sid
+    to_return.sid = not opts.sid and sid_api_client or opts.sid
     to_return.buffer = not opts.buffer and 0 or opts.buffer
     to_return.lnum = not opts.lnum and 0 or opts.lnum
     to_return.desc = opts.desc
@@ -625,7 +628,7 @@ describe('nvim_set_keymap, nvim_del_keymap', function()
   it('interprets control sequences in expr-quotes correctly when called '
      ..'inside vim', function()
     command([[call nvim_set_keymap('i', "\<space>", "\<tab>", {})]])
-    eq(generate_mapargs('i', '<Space>', '\t', {}),
+    eq(generate_mapargs('i', '<Space>', '\t', {sid=0}),
        get_mapargs('i', '<Space>'))
     feed('i ')
     eq({'\t'}, curbufmeths.get_lines(0, -1, 0))
@@ -807,7 +810,7 @@ describe('nvim_set_keymap, nvim_del_keymap', function()
     local mapargs = funcs.maparg('asdf', 'n', false, true)
     assert.Truthy(type(mapargs.callback) == 'number', 'callback is not luaref number')
     mapargs.callback = nil
-    eq(generate_mapargs('n', 'asdf', nil, {}), mapargs)
+    eq(generate_mapargs('n', 'asdf', nil, {sid=sid_lua}), mapargs)
   end)
 
   it('can make lua expr mappings', function()
diff --git a/test/functional/ex_cmds/verbose_spec.lua b/test/functional/ex_cmds/verbose_spec.lua
new file mode 100644
index 0000000000..f1c3d3fe16
--- /dev/null
+++ b/test/functional/ex_cmds/verbose_spec.lua
@@ -0,0 +1,153 @@
+local helpers = require('test.functional.helpers')(after_each)
+
+local clear = helpers.clear
+local eq = helpers.eq
+local exec = helpers.exec
+local exec_capture = helpers.exec_capture
+local write_file = helpers.write_file
+local call_viml_function = helpers.meths.call_function
+
+describe('lua :verbose', function()
+  local script_location, script_file
+  -- All test cases below use the same nvim instance.
+  setup(function()
+    clear{args={'-V1'}}
+    script_file = 'test_verbose.lua'
+    local current_dir = call_viml_function('getcwd', {})
+    current_dir = call_viml_function('fnamemodify', {current_dir, ':~'})
+    script_location = table.concat{current_dir, helpers.get_pathsep(), script_file}
+
+    write_file(script_file, [[
+vim.api.nvim_set_option('hlsearch', false)
+vim.bo.expandtab = true
+vim.opt.number = true
+vim.api.nvim_set_keymap('n', '<leader>key1', ':echo "test"<cr>', {noremap = true})
+vim.keymap.set('n', '<leader>key2', ':echo "test"<cr>')
+
+vim.api.nvim_exec("augroup test_group\
+                     autocmd!\
+                     autocmd FileType c setl cindent\
+                     augroup END\
+                  ", false)
+
+vim.api.nvim_command("command Bdelete :bd")
+vim.api.nvim_add_user_command("TestCommand", ":echo 'Hello'", {})
+
+vim.api.nvim_exec ("\
+function Close_Window() abort\
+  wincmd -\
+endfunction\
+", false)
+]])
+    exec(':source '..script_file)
+  end)
+
+  teardown(function()
+    os.remove(script_file)
+  end)
+
+  it('"Last set" for option set by Lua', function()
+    local result = exec_capture(':verbose set hlsearch?')
+    eq(string.format([[
+nohlsearch
+	Last set from %s line 1]],
+       script_location), result)
+  end)
+
+  it('"Last set" for option set by vim.o', function()
+    local result = exec_capture(':verbose set expandtab?')
+    eq(string.format([[
+  expandtab
+	Last set from %s line 2]],
+       script_location), result)
+  end)
+
+  it('"Last set" for option set by vim.opt', function()
+    local result = exec_capture(':verbose set number?')
+    eq(string.format([[
+  number
+	Last set from %s line 3]],
+       script_location), result)
+  end)
+
+  it('"Last set" for keymap set by Lua', function()
+    local result = exec_capture(':verbose map <leader>key1')
+    eq(string.format([[
+
+n  \key1       * :echo "test"<CR>
+	Last set from %s line 4]],
+       script_location), result)
+  end)
+
+  it('"Last set" for keymap set by vim.keymap', function()
+    local result = exec_capture(':verbose map <leader>key2')
+    eq(string.format([[
+
+n  \key2       * :echo "test"<CR>
+	Last set from %s line 5]],
+       script_location), result)
+  end)
+
+  it('"Last set" for autocmd by vim.api.nvim_exec', function()
+    local result = exec_capture(':verbose autocmd test_group Filetype c')
+    eq(string.format([[
+--- Autocommands ---
+test_group  FileType
+    c         setl cindent
+	Last set from %s line 7]],
+       script_location), result)
+  end)
+
+  it('"Last set" for command defined by nvim_command', function()
+    local result = exec_capture(':verbose command Bdelete')
+    eq(string.format([[
+    Name              Args Address Complete    Definition
+    Bdelete           0                        :bd
+	Last set from %s line 13]],
+       script_location), result)
+  end)
+
+  it('"Last set" for command defined by nvim_add_user_command', function()
+    local result = exec_capture(':verbose command TestCommand')
+    eq(string.format([[
+    Name              Args Address Complete    Definition
+    TestCommand       0                        :echo 'Hello'
+	Last set from %s line 14]],
+       script_location), result)
+  end)
+
+  it('"Last set for function', function()
+    local result = exec_capture(':verbose function Close_Window')
+    eq(string.format([[
+   function Close_Window() abort
+	Last set from %s line 16
+1    wincmd -
+   endfunction]],
+       script_location), result)
+  end)
+end)
+
+describe('lua verbose:', function()
+  local script_file
+
+  setup(function()
+    clear()
+    script_file = 'test_luafile.lua'
+    write_file(script_file, [[
+    vim.api.nvim_set_option('hlsearch', false)
+    ]])
+    exec(':source '..script_file)
+  end)
+
+  teardown(function()
+    os.remove(script_file)
+  end)
+
+  it('is disabled when verbose = 0', function()
+    local result = exec_capture(':verbose set hlsearch?')
+    eq([[
+nohlsearch
+	Last set from Lua]], result)
+  end)
+end)
+