cmd/link: load external ELF PPC64 objects which set st_other=1

This indicates the symbol does not use or preserve the TOC pointer in
R2. Likewise, it does not have a distinct local entry point. This
happens when gcc compiles an object with -mcpu=power10.

Recycle the SymLocalentry field of a text symbol to pass through this
hint as the bogus value 1 (A valid offset must be a multiple of 4
bytes), and update the usage to check and generate errors further into
the linking process. This matches the behavior of st_other as used by
ELFv2.

Change-Id: Ic89ce17b57f400ab44213b21a3730a98c7cdf842
Reviewed-on: https://go-review.googlesource.com/c/go/+/490295
Run-TryBot: Paul Murphy <murp@ibm.com>
Reviewed-by: Cherry Mui <cherryyz@google.com>
Reviewed-by: Dmitri Shuralyov <dmitshur@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>

0 files changed, 0 insertions, 0 deletions