Before:
  Save g:ale_verilog_iverilog_options
  let g:ale_verilog_iverilog_options = ''

After:
  Restore
  call ale#linter#Reset()

Execute(Set Verilog iverilog linter additional options to `-y.`):
  runtime! ale_linters/verilog/iverilog.vim

  " Additional args for the linter
  let g:ale_verilog_iverilog_options = '-y.'

  call ale#Lint()

  let g:cmd = ale_linters#verilog#iverilog#GetCommand(bufnr(''))
  AssertEqual g:cmd, 'iverilog -t null -Wall -y. %t'