LUCENE-2611: ensure temp directories exist when running tests from an IDE

git-svn-id: https://svn.apache.org/repos/asf/lucene/dev/trunk@993199 13f79535-47bb-0310-9956-ffa450edef68

lucene/src/test/org/apache/lucene/util/LuceneTestCaseJ4.java

@@ -140,6 +140,7 @@ public abstract class LuceneTestCaseJ4 {
     if (s == null)
       throw new RuntimeException("To run tests, you need to define system property 'tempDir' or 'java.io.tmpdir'.");
     TEMP_DIR = new File(s);
+    TEMP_DIR.mkdirs();
   }
 
   // by default we randomly pick a different codec for