Before:
  call ale#assert#SetUpLinterTest('asm', 'gcc')
  call ale#test#SetFilename('test.cpp')
  let b:command_tail = ' -x assembler'
  \   . ' -o ' . (has('win32') ? 'nul': '/dev/null')
  \   . '-iquote %s:h'
  \   . ' -Wall -'

After:
  unlet! b:command_tail

  call ale#assert#TearDownLinterTest()

Execute(The executable should be configurable):
  AssertLinter 'gcc', ale#Escape('gcc') . b:command_tail

  let b:ale_asm_gcc_executable = 'foobar'

  AssertLinter 'foobar', ale#Escape('foobar') . b:command_tail