enable --build-id for the kernel link

A Build-ID is an identifier generated at link time to uniquely identify
ELF binaries.  It allows efficient confirmation that an executable or
shared library and a corresponding standalone debuginfo file match.
(Otherwise, a checksum of the debuginfo file must be calculated when
opening it in a debugger.)

The FreeBSD base system includes GNU bfd ld 2.17.50 as the linker for
architectures other than arm64.  Build-ID support was added to bfd ld
shortly after that version, so was not previously available to us.

We can now start making use of Build-ID as we migrate to using lld or
bfd ld from ports, conditionally enabled based on the LINKER_TYPE and
LINKER_VERSION make variables added in r320244 and subsequent commits.

Reviewed by:	dim
MFC after:	3 weeks
Sponsored by:	The FreeBSD Foundation
Differential Revision:	https://reviews.freebsd.org/D11314

0 files changed, 0 insertions, 0 deletions