Support drupal filename extensions in the php lexer

see also: https://github.com/gitlabhq/gitlabhq/issues/8900

lib/rouge/lexers/php.rb

@@ -7,7 +7,10 @@ module Rouge
       desc "The PHP scripting language (php.net)"
       tag 'php'
       aliases 'php', 'php3', 'php4', 'php5'
-      filenames '*.php', '*.php[345]'
+      filenames '*.php', '*.php[345]',
+                # Support Drupal file extensions, see:
+                # https://github.com/gitlabhq/gitlabhq/issues/8900
+                '*.module', '*.inc', '*.profile', '*.install', '*.test'
       mimetypes 'text/x-php'
       default_options :parent => 'html'
@@ -60,6 +63,12 @@ module Rouge
         )
       end
+      def self.analyze_text(text)
+        return 1 if text.shebang?('php')
+        return 0.3 if /<\?(?!xml)/ =~ text
+        0
+      end
+
       state :root do
         rule /<\?(php|=)?/, Comment::Preproc, :php
         rule(/.*?(?=<\?)|.*/m) { delegate parent }