Before:
  runtime ale_linters/cs/mcs.vim

After:
  call ale#linter#Reset()

Execute(The mcs handler should handle cannot find symbol errors):
  AssertEqual
  \ [
  \   {
  \     'lnum': 12,
  \     'col' : 29,
  \     'text': '; expected',
  \     'code': 'CS1001',
  \     'type': 'E',
  \   },
  \   {
  \     'lnum': 101,
  \     'col': 0,
  \     'text': 'Unexpected processor directive (no #if for this #endif)',
  \     'code': 'CS1028',
  \     'type': 'E',
  \   },
  \   {
  \     'lnum': 10,
  \     'col': 12,
  \     'text': 'some warning',
  \     'code': 'CS0123',
  \     'type': 'W',
  \   },
  \ ],
  \ ale_linters#cs#mcs#Handle(347, [
  \   'Tests.cs(12,29): error CS1001: ; expected',
  \   'Tests.cs(101,0): error CS1028: Unexpected processor directive (no #if for this #endif)',
  \   'Tests.cs(10,12): warning CS0123: some warning',
  \   'Compilation failed: 2 error(s), 1 warnings',
  \ ])
