Fix breakage w/ plugins that inadvertently trigger ALE in `execute()` (#3719)

Co-authored-by: w0rp <w0rp@users.noreply.github.com>

autoload/ale/debugging.vim

@@ -259,9 +259,7 @@ function! ale#debugging#InfoToClipboard() abort
         return
     endif
 
-    redir => l:output
-        silent call ale#debugging#Info()
-    redir END
+    let l:output = execute('call ale#debugging#Info()')
 
     let @+ = l:output
     call s:Echo('ALEInfo copied to your clipboard')
@@ -270,9 +268,7 @@ endfunction
 function! ale#debugging#InfoToFile(filename) abort
     let l:expanded_filename = expand(a:filename)
 
-    redir => l:output
-        silent call ale#debugging#Info()
-    redir END
+    let l:output = execute('call ale#debugging#Info()')
 
     call writefile(split(l:output, "\n"), l:expanded_filename)
     call s:Echo('ALEInfo written to ' . l:expanded_filename)

autoload/ale/filetypes.vim

@@ -4,9 +4,7 @@
 function! ale#filetypes#LoadExtensionMap() abort
     " Output includes:
     "    '*.erl setf erlang'
-    redir => l:output
-        silent exec 'autocmd'
-    redir end
+    let l:output = execute('exec "autocmd"')
 
     let l:map = {}
 

autoload/ale/sign.vim

@@ -52,9 +52,7 @@ endif
 function! ale#sign#SetUpDefaultColumnWithoutErrorsHighlight() abort
     let l:verbose = &verbose
     set verbose=0
-    redir => l:output
-        0verbose silent highlight SignColumn
-    redir end
+    let l:output = execute('highlight SignColumn', 'silent')
     let &verbose = l:verbose
 
     let l:highlight_syntax = join(split(l:output)[2:])
@@ -171,10 +169,10 @@ endfunction
 
 " Read sign data for a buffer to a list of lines.
 function! ale#sign#ReadSigns(buffer) abort
-    redir => l:output
-        silent execute 'sign place ' . s:GroupCmd() . s:PriorityCmd()
-        \ . ' buffer=' . a:buffer
-    redir end
+    let l:output = execute(
+    \   'sign place ' . s:GroupCmd() . s:PriorityCmd()
+    \   . ' buffer=' . a:buffer
+    \ )
 
     return split(l:output, "\n")
 endfunction