Pull up following revision(s) (requested by chs in ticket #690):
external/cddl/osnet/dev/dtrace/amd64/dtrace_isa.c: revision 1.4
sys/arch/amd64/include/Makefile.inc: revision 1.4
sys/arch/amd64/include/pmap.h: revision 1.33
external/cddl/osnet/dev/dtrace/amd64/dtrace_subr.c: revision 1.6
sys/arch/amd64/include/asm.h: revision 1.15
sys/arch/amd64/amd64/genassym.cf: revision 1.51
external/cddl/osnet/dev/dtrace/amd64/dtrace_asm.S: revision 1.4
make dtrace work on amd64.
allow more space for modules.