Log Message:
Import rust 1.11.0 as lang/rust into pkgsrc.

pkgsrc notes:

  * The build requires binary bootstraps built by the Rust team.  Due
    to the requirement that only the previous version is supported as
    a bootstrap compiler, and new versions of Rust are released every
    6 weeks, it is unlikely to be practical to build TNF bootstraps.
    Users should evaluate whether they trust binaries from upstream.

  * There is currently no SunOS bootstrap provided by the Rust team,
    so for now a version built by myself is provided by Joyent.

  * Only Darwin/Linux/SunOS are currently supported.  The Rust team do
    provide NetBSD bootstraps so support should be easy enough to add.

Information about Rust from the DESCR:

Rust is a systems programming language focused on three goals: safety,
speed, and concurrency.  It maintains these goals without having a
garbage collector, making it a useful language for a number of use cases
other languages aren't good at: embedding in other languages, programs
with specific space and time requirements, and writing low-level code,
like device drivers and operating systems.

It improves on current languages targeting this space by having a number
of compile-time safety checks that produce no runtime overhead, while
eliminating all data races.  Rust also aims to achieve "zero-cost
abstractions" even though some of these abstractions feel like those of
a high-level language.  Even then, Rust still allows precise control
like a low-level language would.