Add support for multiline messages (#3686)

This is achieved by switching to JSON, which makes it much easier to
avoid confusion between an error message and the next one. It also
spares us from having to deal with regular expressions, and eliminates
some edge cases that no longer need to be tested.

ale_linters/php/phpstan.vim

@@ -32,8 +32,8 @@ function! ale_linters#php#phpstan#GetCommand(buffer, version) abort
     \   : ''
 
     let l:error_format = ale#semver#GTE(a:version, [0, 10, 3])
-    \   ? ' --error-format raw'
-    \   : ' --errorFormat raw'
+    \   ? ' --error-format json'
+    \   : ' --errorFormat json'
 
     return '%e analyze --no-progress'
     \   . l:error_format
@@ -44,17 +44,17 @@ function! ale_linters#php#phpstan#GetCommand(buffer, version) abort
 endfunction
 
 function! ale_linters#php#phpstan#Handle(buffer, lines) abort
-    " Matches against lines like the following:
-    "
-    " filename.php:15:message
-    " C:\folder\filename.php:15:message
-    let l:pattern = '^\([a-zA-Z]:\)\?[^:]\+:\(\d\+\):\(.*\)$'
+    let l:res = ale#util#FuzzyJSONDecode(a:lines, {'files': []})
     let l:output = []
 
-    for l:match in ale#util#GetMatches(a:lines, l:pattern)
+    if type(l:res.files) is v:t_list
+        return l:output
+    endif
+
+    for l:err in l:res.files[expand('#' . a:buffer .':p')].messages
         call add(l:output, {
-        \   'lnum': l:match[2] + 0,
-        \   'text': l:match[3],
+        \   'lnum': l:err.line,
+        \   'text': l:err.message,
         \   'type': 'E',
         \})
     endfor