AST cleanup (dropped AST_StatementBase)

lib/compress.js

@@ -162,7 +162,7 @@ merge(Compressor.prototype, {
         if (thing === null) return [];
         if (thing instanceof AST_BlockStatement) return thing.body;
         if (thing instanceof AST_EmptyStatement) return [];
-        if (thing instanceof AST_StatementBase) return [ thing ];
+        if (thing instanceof AST_Statement) return [ thing ];
         throw new Error("Can't convert thing to statement array");
     };
 
@@ -741,7 +741,7 @@ merge(Compressor.prototype, {
         return thing && thing.aborts();
     };
     (function(def){
-        def(AST_StatementBase, function(){ return null });
+        def(AST_Statement, function(){ return null });
         def(AST_Jump, function(){ return this });
         def(AST_BlockStatement, function(){
             var n = this.body.length;