Add support for shellcheck linting.

ale_linters/c/gcc.vim

@@ -9,35 +9,6 @@ if !exists('g:ale_c_gcc_options')
     let g:ale_c_gcc_options = '-Wall'
 endif
 
-function! ale_linters#c#gcc#Handle(buffer, lines)
-    " Look for lines like the following.
-    "
-    " <stdin>:8:5: warning: conversion lacks type at end of format [-Wformat=]
-    " <stdin>:10:27: error: invalid operands to binary - (have ‘int’ and ‘char *’)
-    let pattern = '^<stdin>:\(\d\+\):\(\d\+\): \(warning\|error\): \(.\+\)$'
-    let output = []
-
-    for line in a:lines
-        let l:match = matchlist(line, pattern)
-
-        if len(l:match) == 0
-            continue
-        endif
-
-        call add(output, {
-        \   'bufnr': a:buffer,
-        \   'lnum': l:match[1] + 0,
-        \   'vcol': 0,
-        \   'col': l:match[2] + 0,
-        \   'text': l:match[4],
-        \   'type': l:match[3] ==# 'warning' ? 'W' : 'E',
-        \   'nr': -1,
-        \})
-    endfor
-
-    return output
-endfunction
-
 call ALEAddLinter('c', {
 \   'name': 'gcc',
 \   'output_stream': 'stderr',
@@ -45,5 +16,5 @@ call ALEAddLinter('c', {
 \   'command': 'gcc -S -x c -fsyntax-only '
 \       . g:ale_c_gcc_options
 \       . ' -',
-\   'callback': 'ale_linters#c#gcc#Handle',
+\   'callback': 'ale#handlers#HandleGCCFormat',
 \})