Reserve the `alignof`, `offsetof`, and `sizeof` keywords
Closes #9333.
auto merge of #9389 : poiru/rust/issue-9333, r=alexcrichton

Closes #9333.
disable starvation test completely for now

this is still broken on the bsd builder, perhaps because it has 1 core
auto merge of #9412 : thestinger/rust/no_starve_xfail, r=cmr

this is still broken on the bsd builder, perhaps because it has 1 core