Fix regression breaking filters with --prefixed pseudo-elements

Related feedback:
- uBlockOrigin/uBlock-issues#89 (comment)

src/js/static-filtering-parser.js

@@ -1177,7 +1177,7 @@ Parser.prototype.SelectorCompiler = class {
  ]);
  this.reSimpleSelector = /^[#.][A-Za-z_][\w-]*$/;
  this.div = document.createElement('div');
- this.rePseudoClass = /:(?::?after|:?before|:[a-z][a-z-]*[a-z])$/;
+ this.rePseudoClass = /:(?::?after|:?before|:-?[a-z][a-z-]*[a-z])$/;
  this.reProceduralOperator = new RegExp([
  '^(?:',
  Array.from(parser.proceduralOperatorTokens.keys()).join('|'),