fix beautify whitespace output within AST_Destructuring (#2046)

fixes #2044

lib/output.js

@@ -805,17 +805,15 @@ function OutputStream(options) {
 
     DEFPRINT(AST_Destructuring, function (self, output) {
         output.print(self.is_array ? "[" : "{");
-        var first = true;
         var len = self.names.length;
         self.names.forEach(function (name, i) {
-            if (first) first = false; else { output.comma(); output.space(); }
+            if (i > 0) output.comma();
             name.print(output);
             // If the final element is a hole, we need to make sure it
             // doesn't look like a trailing comma, by inserting an actual
             // trailing comma.
-            if (i === len - 1 && name instanceof AST_Hole)
-              output.comma();
-        })
+            if (i == len - 1 && name instanceof AST_Hole) output.comma();
+        });
         output.print(self.is_array ? "]" : "}");
     });
 
@@ -1577,7 +1575,9 @@ function OutputStream(options) {
             get_name(self.value.left) === self.key
         ) {
             print_property_name(self.key, self.quote, output);
+            output.space();
             output.print("=");
+            output.space();
             self.value.right.print(output);
         } else {
             if (!(self.key instanceof AST_Node)) {