[12] RFR(XS) 8209023: fix 2 compiler tests to avoid JDK-8208690

[Vladimir Kozlov]

https://bugs.openjdk.java.net/browse/JDK-8209023

Some test starts separate threads with long execution time (sleep and loops). Main thread may exit before other threads 
are finished and jtreg has issues with leftover threads.
Add /othervm to run command to make sure no threads left running by executing test in separate process.
I don't think we should change test's code.

Verified that test passed with and without -Xcomp (no timeouts).

diff -r 82adcc8ad853 test/hotspot/jtreg/compiler/runtime/cr6891750/Test6891750.java
--- a/test/hotspot/jtreg/compiler/runtime/cr6891750/Test6891750.java
+++ b/test/hotspot/jtreg/compiler/runtime/cr6891750/Test6891750.java
@@ -1,5 +1,5 @@
  /*
- * Copyright (c) 2009, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2009, 2018, Oracle and/or its affiliates. All rights reserved.
   * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   *
   * This code is free software; you can redistribute it and/or modify it
@@ -25,7 +25,7 @@
   * @test
   * @bug 6891750
   * @summary deopt blob kills values in O5
- * @run main compiler.runtime.cr6891750.Test6891750
+ * @run main/othervm compiler.runtime.cr6891750.Test6891750
   */

  package compiler.runtime.cr6891750;

-- 
Thanks,
Vladimir