PR go/46958 PR go/46965 Call __builtin_return_address with 0 rather than 1.
PR go/46958
PR go/46965
Call __builtin_return_address with 0 rather than 1.

R=iant
CC=gofrontend-dev
https://golang.org/cl/3798047

anlhord/gofrontend,anlhord/gofrontend,anlhord/gofrontend,qskycolor/gofrontend,qskycolor/gofrontend,anlhord/gofrontend,qskycolor/gofrontend,anlhord/gofrontend,qskycolor/gofrontend,golang/gofrontend,qskycolor/gofrontend,golang/gofrontend,anlhord/gofrontend,golang/gofrontend,qskycolor/gofrontend,anlhord/gofrontend,golang/gofrontend,qskycolor/gofrontend