Add gtest run with -XX:+UseLargePages

gtests need to be run, as part of the hotspot jtreg tests (test/hotspot/jtreg/gtest/GTestWrapper.java), with -XX:+UseLargePages (and potentially one separate run with -XX:LargePageSizeInBytes=1G).

Potentially we can omit a lot of the gtests but at least the "os" tests should be run.

We already do this for metaspace tests, so this can serve an example, see: test/hotspot/jtreg/gtest/MetaspaceGtests.java

The tests should run even if the system does not have enough huge pages allocated, since even then part of the huge page initialization is done.

Note: https://bugs.openjdk.java.net/browse/JDK-8257229 hampers this a bit, since if huge page allocation fails we print out unconditionally a warning to stderr which may confuse gtest death tests. So either that has to be solved or the death tests have to be excluded.