File Highlight: Fixed IE compatibility problem (#2656)

The File Highlight plugin used the `Element#matches` which isn't supported by IE11, so a small polyfill was added.

plugins/file-highlight/prism-file-highlight.js

@@ -3,6 +3,11 @@
 		return;
 	}
 
+	// https://developer.mozilla.org/en-US/docs/Web/API/Element/matches#Polyfill
+	if (!Element.prototype.matches) {
+		Element.prototype.matches = Element.prototype.msMatchesSelector || Element.prototype.webkitMatchesSelector;
+	}
+
 	var Prism = window.Prism;
 
 	var LOADING_MESSAGE = 'Loading…';

prism.js

@@ -1566,6 +1566,11 @@ Prism.languages.js = Prism.languages.javascript;
 		return;
 	}
 
+	// https://developer.mozilla.org/en-US/docs/Web/API/Element/matches#Polyfill
+	if (!Element.prototype.matches) {
+		Element.prototype.matches = Element.prototype.msMatchesSelector || Element.prototype.webkitMatchesSelector;
+	}
+
 	var Prism = window.Prism;
 
 	var LOADING_MESSAGE = 'Loading…';