Rollup of 6 pull requests#41373

Merged

bors merged 20 commits intorust-lang:masterfrom

frewsxcv:rollup

Apr 18, 2017

Commits on Apr 16, 2017

Fix stdio descriptors in exec by removing cloexec if present. Use dup2 instead of dup
jackpot51
committed

Commits on Apr 17, 2017

fix: remove `field_init_shorthand` from SUMMARY.md
3Hren
committed

Commits on Apr 18, 2017