Remove CloudABI Binutils tools.

As of FreeBSD 11, the cloudabi-toolchain port uses the ELF-toolchain
utilities for all the stuff not provided by LLVM. For FreeBSD 10 and
lower, we still rely on Binutils.

As CloudABI itself is only supported as of FreeBSD 11, there is hardly
any interest in supporting a Binutils based toolchain. Let's kick out
the CloudABI Binutils ports and symlink to the utilities in the base
system unconditionally.

Reviewed by:	rene
Differential Revision:	https://reviews.freebsd.org/D11733

Update to 2.27

Remove aarch64 patches which are now upstream
Disable new x86 relocation to avoid incompatibilities with the old base binutils
Activate all targets on the default binutils (requested by royger@)
Add a RELRO option (default off) to be able to define the default behaviour of
ld(1) on passing or not -z relro

Switch the cloudabi-toolchain port over to llvm-devel.

Farnsworth: "Good news, everyone!" The latest revisions of LLVM trunk
not only have a version of LLD that creates usable binaries for x86-64
and aarch64, it also does a better job at creating Position Independent
Executables than the GNU linker.

Because PIE is going to become pretty important for some of the upcoming
projects (emulation on other OSes), I'd like to go ahead and switch the
cloudabi-toolchain port over to the latest snapshot of LLVM. My goal is
to revert back to a stable version (3.9) when available.

Switching to LLD involves patching up the Binutils ports to no longer
install the GNU linker (and remove the linker scripts that it uses). We
can then simply add a couple of extra symlinks to cloudabi-toolchain to
point to the LLD binary.

At the same time, let's switch over to using the ELF toolchain tools on
FreeBSD 11. That way we can even drop the dependency on Binutils on
those systems.

Reviewed by:	bapt, emaste
Differential Revision:	https://reviews.freebsd.org/D5874

Extend the Binutils ports to allow deletion of specific tools.

For CloudABI I slowly want to switch away from certain tools provided by
Binutils. For example, it would be really nice if we could switch from
GNU ld to LLD some time in the future. LLD is not ready yet. Some bug
fixes didn't manage to land into 3.8 and it doesn't support aarch64
properly. There are already some tools that we can use, such as nm,
objdump, size, ar and ranlib.

Introduce a BUREMOVE variable that can be set in Binutils slave ports to
remove specific utilities that are installed by default. There doesn't
seem to be any other elegant way to solve this. Set a bunch of utilities
by default and then extend cloudabi-clang to set up symlinks to the LLVM
versions of the tools.

Reviewed by:	bapt
Differential Revision:	https://reviews.freebsd.org/D5684

Revert update to binutils 2.25.1 and bump portepoch to reflect that revert

binutils has build issues on 10.x i386 and is full of regressions on 9.x:
unexpected build failures on nss and others

Reported by:	antoine
Pointyhat to:	bapt

Update to binutils 2.26 which includes the cloudabi support natively

Introduce Binutils for CloudABI on aarch64.

When I added the first copy of the CloudABI toolchain to the Ports tree,
I assumed that it would be easily possible to have a single Binutils
port that would support all of the architectures of interest. It seems
that this is not really supported, or simply awkward to use.

Let's just rename the cloudabi-binutils port to cloudabi-binutils-x86_64
and add an additional cloudabi-binutils-aarch64.

Reviewed by:	emaste
Approved by:	bapt
Differential Revision:	https://reviews.freebsd.org/D3919