Remove temp directories in tests

There's new algo for temp file creation that starting to fail after ~1000 files have been created.

compiler/tests/org/jetbrains/kotlin/test/KotlinTestWithEnvironment.java

@@ -31,11 +31,13 @@ public abstract class KotlinTestWithEnvironment extends KotlinTestWithEnvironmen
 
     @Override
     protected void tearDown() throws Exception {
+        removeEnvironment();
         environment = null;
         super.tearDown();
     }
 
     protected abstract KotlinCoreEnvironment createEnvironment() throws Exception;
+    protected void removeEnvironment() throws Exception {}
 
     @NotNull
     public KotlinCoreEnvironment getEnvironment() {