test(old): add more missing test files and run more tests alone

Copy four files from Vim v8.2.1432.
Try to match Vim's test_alot.vim.
This marks Vim patch 8.2.0164 as ported:

vim-patch:8.2.0164: test_alot takes too long

Problem:    Test_alot takes too long.
Solution:   Run several tests individually.
https://github.com/vim/vim/commit/842931cd7af37ea95e826b7a93a5d5587d18c9bb

1 files changed, 0 insertions, 30 deletions

diff --git a/test/functional/legacy/set_spec.lua b/test/functional/legacy/set_spec.lua
deleted file mode 100644
index deb268b1e8..0000000000
--- a/test/functional/legacy/set_spec.lua
+++ /dev/null
@@ -1,30 +0,0 @@
--- Tests for :set
-
-local helpers = require('test.functional.helpers')(after_each)
-local clear, command, eval, eq =
-  helpers.clear, helpers.command, helpers.eval, helpers.eq
-
-describe(':set', function()
-  before_each(clear)
-
-  it('handles backslash properly', function()
-    command('set iskeyword=a,b,c')
-    command('set iskeyword+=d')
-    eq('a,b,c,d', eval('&iskeyword'))
-
-    command([[set iskeyword+=\\,e]])
-    eq([[a,b,c,d,\,e]], eval('&iskeyword'))
-
-    command('set iskeyword-=e')
-    eq([[a,b,c,d,\]], eval('&iskeyword'))
-
-    command([[set iskeyword-=\]])
-    eq('a,b,c,d', eval('&iskeyword'))
-  end)
-
-  it('recognizes a trailing comma with +=', function()
-    command('set wildignore=*.png,')
-    command('set wildignore+=*.jpg')
-    eq('*.png,*.jpg', eval('&wildignore'))
-  end)
-end)