improve performance (#3020)

- replace `find_if()` with `all()` wherever possible
- move ESTree-specific logic out of `figure_out_scope()`

lib/parse.js

@@ -969,7 +969,9 @@ function parse($TEXT, options) {
 
     function labeled_statement() {
         var label = as_symbol(AST_Label);
-        if (find_if(function(l){ return l.name == label.name }, S.labels)) {
+        if (!all(S.labels, function(l) {
+            return l.name != label.name;
+        })) {
             // ECMA-262, 12.12: An ECMAScript program is considered
             // syntactically incorrect if it contains a
             // LabelledStatement that is enclosed by a