Defer Apple SDKROOT detection to link time.#77202

Merged

bors merged 3 commits intorust-lang:masterfrom ehuss:defer-apple-sdkroot

Oct 1, 2020

+114-139

Commits on Sep 25, 2020

Commits on Sep 27, 2020

Move add_apple_sdk out of add_pre_link_args.
ehuss
committed