[dev.link] cmd/link: convert Link.linksetup method to work with loader
Switch the linker's Link.linksetup method to work with loader.Sym
instead of sym.Symbols. Currently enabled when the new ELF host object
loader is turned on.
Change-Id: I336cc9f36166767baac574455531e195b6f1ac57
Reviewed-on: https://go-review.googlesource.com/c/go/+/213423
Run-TryBot: Than McIntosh <thanm@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Jeremy Faller <jeremy@golang.org> Reviewed-by: Cherry Zhang <cherryyz@google.com>