update to higlight.js 8.4

vendor/assets/javascripts/highlight_js/languages/php.js

@@ -2,11 +2,12 @@
 Language: PHP
 Author: Victor Karamzin <Victor.Karamzin@enterra-inc.com>
 Contributors: Evgeny Stepanischev <imbolk@gmail.com>, Ivan Sagalaev <maniac@softwaremaniacs.org>
+Category: common
 */
 
 function(hljs) {
   var VARIABLE = {
-    className: 'variable', begin: '(\\$|->)+[a-zA-Z_\x7f-\xff][a-zA-Z0-9_\x7f-\xff]*'
+    className: 'variable', begin: '\\$+[a-zA-Z_\x7f-\xff][a-zA-Z0-9_\x7f-\xff]*'
   };
   var PREPROCESSOR = {
     className: 'preprocessor', begin: /<\?(php)?|\?>/
@@ -64,6 +65,10 @@ function(hljs) {
       },
       PREPROCESSOR,
       VARIABLE,
+      {
+        // swallow class members to avoid parsing them as keywords
+        begin: /->+[a-zA-Z_\x7f-\xff][a-zA-Z0-9_\x7f-\xff]*/
+      },
       {
         className: 'function',
         beginKeywords: 'function', end: /[;{]/, excludeEnd: true,
@@ -88,10 +93,7 @@ function(hljs) {
         beginKeywords: 'class interface', end: '{', excludeEnd: true,
         illegal: /[:\(\$"]/,
         contains: [
-          {
-            beginKeywords: 'extends implements',
-            relevance: 10
-          },
+          {beginKeywords: 'extends implements'},
           hljs.UNDERSCORE_TITLE_MODE
         ]
       },