Add travis builders for Rust without fragile-hardening

We're having problems getting fragile hardening to link reliably with Rust's tests. Until we get them solved, we should have some travis builders to make sure that Rust still works when the C hardening is not turned on.

changed milestone to %Tor: 0.3.4.x-final in legacy/trac

added 034-must in Legacy / Trac ci in Legacy / Trac component::core tor/tor in Legacy / Trac milestone::Tor: 0.3.4.x-final in Legacy / Trac owner::catalyst in Legacy / Trac points::1 in Legacy / Trac priority::medium in Legacy / Trac resolution::implemented in Legacy / Trac reviewer::isis in Legacy / Trac rust in Legacy / Trac rust-linking in Legacy / Trac severity::normal in Legacy / Trac sponsor::M-can in Legacy / Trac status::closed in Legacy / Trac type::defect in Legacy / Trac labels

Trac:
Keywords: ci deleted, ci rust rust-linking added

Trac:
Status: new to assigned
Owner: N/A to catalyst

While working on this I discovered that distcheck doesn't work with rust in offline mode. I'll work around it for now.

Patch in https://github.com/torproject/tor/pull/171

Trac:
Status: assigned to needs_review

Trac:
Reviewer: N/A to isis

LGTM!

Trac:
Status: needs_review to merge_ready
Points: N/A to 1
Sponsor: N/A to SponsorM-can

Great; merged!

Trac:
Keywords: ci rust rust-linking deleted, ci rust rust-linking 034-must added
Status: merge_ready to closed
Resolution: N/A to implemented

What's the issue here?

closed

changed time estimate to 8h

moved from legacy/trac#26449 (moved)

added Bug label and removed 1 deleted label

added CI Rust labels and removed 1 deleted label