MFC r265824:
Print the entry address in addition to the object.
MFC r265825:
When printing the map with the ddb 'show procvm' command, do not dump
page queues for the backing objects.
MFC r265843:
For the upgrade case in vm_fault_copy_entry(), when the entry does not
need COW and is writeable, do not create a new backing object for the entry.

MFC r265887:
Fix locking.
MFC r265845:
Style.