[PATCH 0/8] Add Rust language support

[Tom Tromey <tom@tromey.com>]

Hi.  It's been a while.

This patch series adds support for the Rust programming languages to
gdb.  See https://www.rust-lang.org/ for more information on Rust
itself.

This is a reasonably full-featured port.  It has a few known bugs and
holes, but nothing very serious.

I've tested it using Rust 1.8, as available in the Fedora COPR.  It's
known not to work with Rust nightly, due to some debuginfo regressions
there.

I ran the new tests with gcov.  The test cases cover 98% of
rust-exp.y, and 82% of rust-lang.c -- mostly missing things like
rust_print_subexp; I intentionally didn't write tests for the
expression-dumping debug functions.

I wrote most of the code, but Manish Goregaokar did some as well --
more than enough to require an assignment.  Both of our copyright
assignments are in process.

I've built the series both with gcc and with g++.

I'd like to make a new rust component in bugzilla once this is
approved.

If anybody cares, I have a list of the ugly bits in gdb I encountered
while writing this series.  I think it's all generally well known
though.

Please review.  Thanks.

Tom