Revert "cmd/link: use path from "cc --print-prog-name ar" for c-archive buildmode"

Revert "cmd/link: use path from "cc --print-prog-name ar" for c-archive buildmode"

This reverts commit https://go-review.git.corp.google.com/c/go/+/479775

Reason for revert: fails with ios-arm64-corellium builder

Change-Id: Iae61b994a39ff6c70af8a302f7a46de0097edf3e
Reviewed-on: https://go-review.googlesource.com/c/go/+/479917
Auto-Submit: Than McIntosh <thanm@google.com>
Run-TryBot: Than McIntosh <thanm@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@google.com>