apply performance bug hint from intellij

src/main/jastadd/DumpTree.jrag

@@ -33,7 +33,7 @@ aspect DumpTree {
   public String ASTNode.extraDumpInfo() { return ""; }
 
   public String ASTNode.getTokens() {
-    java.util.TreeSet<java.lang.reflect.Method> methods = new java.util.TreeSet<>(Comparator.comparing(Method::getName));
+    java.util.TreeSet<java.lang.reflect.Method> methods = new java.util.TreeSet<>(Comparator.comparing(java.lang.reflect.Method::getName));
 
     methods.addAll(java.util.Arrays.asList(getClass().getMethods()));
 
@@ -43,7 +43,8 @@ aspect DumpTree {
       if (token != null) {
         try {
           result.append(String.format(" %s=\"%s\"", token.name(), method.invoke(this)));
-        } catch (IllegalAccessException | java.lang.reflect.InvocationTargetException ignored) {
+        } catch (IllegalAccessException  ignored) {
+        } catch (java.lang.reflect.InvocationTargetException ignored) {
         }
       }
     }

src/main/jastadd/backend/PrettyPrinting.jadd

@@ -33,10 +33,10 @@ aspect PrettyPrinting {
 
 aspect Utils {
   public String ASTNode.ind(int n) {
-    String s = "";
+    StringBuilder s = new StringBuilder();
     for (int i = 0; i < n; i++) {
-      s += "  ";
+      s.append("  ");
     }
-    return s;
+    return s.toString();
   }
 }