BUILD: sym: Build properly with gold as a linker

BUILD: sym: Build properly with gold as a linker

Some linkers, such as gold, will not let us do our trick of having our
note in our own program header, and will merge it with other notes. If
that happens, then detect it, and just link the binary a second time,
now that we know the size of the section, as we created the xz file
already, we can add it without wasting any binary space.