The -lldb flag makes it easy to use go run and end up in a debugging
session on darwin/arm.

Change-Id: I556f93e950086a7dff4839f301b9c55f7579f87b
Reviewed-on: https://go-review.googlesource.com/8024Reviewed-by: Hyang-Ah Hana Kim <hyangah@gmail.com>