Use position-bytes function instead of point

I thought this was intuitively a problem of phpactor/worse-reflection,
but in fact it is a problem of Tolerant PHP Parser.
https://github.com/Microsoft/tolerant-php-parser

In modern environments it is obsolete to operate in byte units instead
of character units, but Tolerant PHP Parser's current implementation
adopt byte offsets.

Author: zonuexe

phpactor.el

@@ -216,7 +216,7 @@
               (point-min) (point-max)))
     (:path (phpactor--expand-local-file-name buffer-file-name))
     (:source_path (phpactor--expand-local-file-name buffer-file-name))
-    (:offset (1- (point)))
+    (:offset (1- (position-bytes (point))))
     (:current_path (phpactor--expand-local-file-name buffer-file-name))
     (t (error "`%s' is unknown argument" key))))