The Go toolchain used to require that we rebuild the compiler and
friends (the cgo command) when building a cgo-enabled cross compiler.
This meant that gomobile init used to invoke make.bash in a temporary
copy of the GOROOT. This works, but brings with it several
complications, including needing to use -toolexec when invoking the
go tool, finding a boostrap copy of Go 1.4, long initialization
times, and a variety of unusual failure modes.
Fortunately we don't need our own compiler any more. All that's
necessary is building the standard library for the cross-compilation
targets and making sure the right C compiler is used when calling
go build (as it always was). This means most of the initialization
process can be replaced with a carefully invoked 'go install std'.
While here, remove the source install instructions (most of it is
documented already, and the final step, choosing the right git
revision should be within the skills of anyone using pre-release
software.) Some other documentation is changing because it's been a
while since go generate was run.
Change-Id: I88c10fef87867536e83c7df063ae7241b2e9eea4
Reviewed-on: https://go-review.googlesource.com/11711
Reviewed-by: Hyang-Ah Hana Kim <hyangah@gmail.com>
743b9bfd9a