The xcoff writer has several "ldr.SymVersion(s) != 0" checks. The
intent of these is to check for file-local (or static) symbols. Prior
to the introduction of symbol ABIs, this was indeed equivalent since
only file-local symbols has non-zero versions, but ABIs also use the
symbol version space. This still happened to work until much more
recently because we were only ever cgo-exporting version 0 symbols,
but CL 309341 changed this, causing these checks to fail on symbols
that were okay to export.