MFC r312514:

Use SRCTOP-relative paths to other directories instead of .CURDIR-relative ones

This simplifies pathing in make/displayed output

Copy head@r302406 to stable/11 as part of the 11.0-RELEASE cycle.
Prune svn:mergeinfo from the new branch, as nothing has been merged
here.

Additional commits post-branch will follow.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

Add META_MODE support.

Off by default, build behaves normally.
WITH_META_MODE we get auto objdir creation, the ability to
start build from anywhere in the tree.

Still need to add real targets under targets/ to build packages.

Differential Revision: D2796
Reviewed by: brooks imp

MFtbemd:

Prefer MACHNE_CPUARCH to MACHINE_ARCH in most contexts where you want
to test of all the CPUs of a given family conform.

Make this directory more regular. Since it is one we control, use the
freebsd-based names for filenames. This allows us to eliminate
almost all of the uses of ${MACHINE_ARCH} here to do special things, and
instead we use it to include filenames. This makes new architectures easier
to support.

Initial gdbserver support for amd64.

Initial gdbserver support for PowerPC.

Obtained from: Juniper Networks, Semihalf

Initial gdbserver support for ARM.

Obtained from: Juniper Networks, Semihalf

bring in the necessary changes to make gdbserver compile and work (at
least on i386)... fbsd-* changes started out as s/linux/fbsd/g and then
additional changes to handle different ptrace defines among other things..
(use vfork to eliminate a race for progress group creation)

reg-i386.c is generated by regdat.sh..

This commit was generated by cvs2svn to compensate for changes in r157571,
which included commits to RCS files with non-trunk default branches.