Add test and close #8893
Silence some unused import warnings
Correctly reset steals when hitting MAX_STEALS

The previous code erroneously assumed that 'steals > cnt' was always true, but
that was a false assumption. The code was altered to decrement steals to a
minimum of 0 instead of taking all of cnt into account.

I didn't include the exact test from #12295 because it could run for quite
awhile, and instead set the threshold for MAX_STEALS to much lower during
testing. I found that this triggered the old bug quite frequently when running
without this fix.

Closes #12295
auto merge of #12301 : FlaPer87/rust/issue-8893, r=alexcrichton
mk: Remove check-notidy, check-full, check-test

Mostly useless
mk: Fix typo, NO_MAKEFILE_DEPS -> NO_MKFILE_DEPS
auto merge of #12302 : alexcrichton/rust/issue-12295, r=brson

The previous code erroneously assumed that 'steals > cnt' was always true, but
that was a false assumption. The code was altered to decrement steals to a
minimum of 0 instead of taking all of cnt into account.

I didn't include the exact test from #12295 because it could run for quite
awhile, and instead set the threshold for MAX_STEALS to much lower during
testing. I found that this triggered the old bug quite frequently when running
without this fix.

Closes #12295
auto merge of #12310 : brson/rust/mkfilecleanup, r=sfackler

Two small fixes