Add missing space to gcc linter (dense-analysis#4791). (dense-analysis#5088)

Co-authored-by: Mathis Bernadet <matbernadet@emi.u-bordeaux.fr>

Author: Mat33920

ale_linters/asm/gcc.vim

@@ -9,7 +9,7 @@ function! ale_linters#asm#gcc#GetCommand(buffer) abort
     " -fsyntax-only doesn't catch everything.
     return '%e -x assembler'
     \   . ' -o ' . g:ale#util#nul_file
-    \   . '-iquote %s:h'
+    \   . ' -iquote %s:h'
     \   . ' ' . ale#Var(a:buffer, 'asm_gcc_options') . ' -'
 endfunction
 

test/linter/test_asm_gcc.vader

@@ -3,7 +3,7 @@ Before:
   call ale#test#SetFilename('test.cpp')
   let b:command_tail = ' -x assembler'
   \   . ' -o ' . (has('win32') ? 'nul': '/dev/null')
-  \   . '-iquote %s:h'
+  \   . ' -iquote %s:h'
   \   . ' -Wall -'
 
 After: