feat(autocmd): add Recording autocmds

feat(eval): add reg_recorded()

This function is used the get the last recorded register.

style(Recording): rename handler to match suggestions

fix(RecordingLeave): send autocommand earlier

This makes the autocommand fire just before setting reg_recorded to
reg_recording, this way we clearly show that we are actually just before
actually quitting the recording mode.

test/functional/editor/macro_spec.lua

@@ -6,6 +6,8 @@ local feed = helpers.feed
 local clear = helpers.clear
 local expect = helpers.expect
 local command = helpers.command
+local insert = helpers.insert
+local curbufmeths = helpers.curbufmeths
 
 describe('macros', function()
   before_each(clear)
@@ -27,4 +29,29 @@ describe('macros', function()
     expect('llllll')
     eq(eval('@i'), 'lxxx')
   end)
+
+  it('can be replayed with Q', function()
+    insert [[hello
+hello
+hello]]
+    feed [[gg]]
+
+    feed [[qqAFOO<esc>q]]
+    eq({'helloFOO', 'hello', 'hello'}, curbufmeths.get_lines(0, -1, false))
+
+    feed[[Q]]
+    eq({'helloFOOFOO', 'hello', 'hello'}, curbufmeths.get_lines(0, -1, false))
+
+    feed[[G3Q]]
+    eq({'helloFOOFOO', 'hello', 'helloFOOFOOFOO'}, curbufmeths.get_lines(0, -1, false))
+  end)
+end)
+
+describe('reg_recorded()', function()
+  before_each(clear)
+
+  it('returns the correct value', function()
+    feed [[qqyyq]]
+    eq('q', eval('reg_recorded()'))
+  end)
 end)