Add crate build test for `thumb*` targets. [IRR-2018-embedded]#53190

Merged

bors merged 15 commits intorust-lang:masterfrom

sekineh:thumb-cortex-m

Aug 17, 2018

Commits on Aug 7, 2018

[CI] run-make/thumb: 1st working version with hacky workaround.
sekineh
committed

Commits on Aug 10, 2018

[CI] run-make/thumb: remove `-j 1` from cargo run
sekineh
committed