8027294: Prepare hotspot for non TOD based uptime counter Summary: Use HR timer when available for os::elapsed_counter() on linux/bsd. Add a new counter for the JVM uptime. Reviewed-by: dholmes, sla

8020753: JNI_CreateJavaVM on Mac OSX 10.9 Mavericks corrupts the callers stack size Summary: Use hard-coded DEFAULT_MAIN_THREAD_STACK_PAGES = 2048 for 10.9 Reviewed-by: dcubed, iveresov Contributed-by: gerard.ziemski@oracle.com