8079148: Fix incorrect include guards
Reviewed-by: stefank, ehelin

8036701: Add trace event when a metaspace throws out of memory error
Reviewed-by: stefank, mgerdin

8036699: Add trace event when a metaspace allocation fails
Reviewed-by: jmasa, stefank

8036698: Add trace event for updates to metaspace gc threshold
Reviewed-by: stefank, mgerdin