The Go runtime doesn't handle SIGIPE signals from writing to closed
sockets or pipes in c-archive and c-shared mode (issue 17393).
Work around it in gomobile by simply ignoring all SIGPIPE signals;
they're not useful in mobile apps anyway.
Change-Id: Ibd7ee41058856c5eddb4a519345a3851a29e9b44
Reviewed-on: https://go-review.googlesource.com/33771
Reviewed-by: David Crawshaw <crawshaw@golang.org>