Increasing KVM on amd64

[Artem Belevich]

By the way, this part of Alan's patch fixes a bug in RELENG7 where
mapbase is passed to vm_map_find uninitialized. -CURRENT already has
this change applied. Perhaps it's worth committing in RELENG7, too.

--- ./kern/link_elf_obj.c.orig  2008-09-01 11:06:44.000000000 -0700
+++ ./kern/link_elf_obj.c       2008-09-10 13:07:54.793310216 -0700
@@ -667,6 +667,7 @@
               goto out;
       }
       ef->address = (caddr_t) vm_map_min(kernel_map);
+       mapbase = KERNBASE;
       error = vm_map_find(kernel_map, ef->object, 0, &mapbase,
           round_page(mapsize), TRUE, VM_PROT_ALL, VM_PROT_ALL, FALSE);
       if (error) {

--Artem