Call for testing: Using ELF Tool Chain elfcopy as objcopy

Summary: If you're willing to help test the ELF Tool Chain tools and
you build -CURRENT from source, please set WITH_ELFCOPY_AS_OBJCOPY=yes
in /etc/src.conf, and report any build- or run-time issues you
experience with the base system, ports, or third-party software.

In SVN revision 295577 I updated ELF Tool Chain to upstream revision
3400, which corresponds roughly with the upcoming 0.7.1 release of
that project.  ELF Tool Chain's elfcopy is a functional replacement
for binutils objcopy for both the base system and ports tree after
this update and a few followup commits. (An exp-run is in progress in
PR 207091 to validate the followup fixes. One port failure is due to
an issue in that port and is tracked in PR 207170.)

There is a src.conf knob WITH_ELFCOPY_AS_OBJCOPY to install ELF Tool
Chain's elfcopy as /usr/bin/objcopy. I plan to make this the default
for 11.0, but first would like to ask for broader testing with the
setting enabled. I'm particularly interested in hearing from anyone
using the base system objcopy in unusual cases (e.g., converting ELF
files to ROM images).

Note that some lesser-used objcopy options (like --reverse-bytes or
--interleave-width) are not implemented in elfcopy, so I'm also
interested in hearing from anyone who makes use of options that are
not supported by elfcopy.