Register new snapshots

Time for a visit from the snapshot fairy!
std::vec: replace .insert with a small amount of unsafe code.

This makes the included benchmark more than 3 times faster. Also,
`.unshift(x)` is now faster as `.insert(0, x)` which can reuse the
allocation if necessary.
std::str: fix .slice_chars example. Fixes #11014.
auto merge of #11050 : alexcrichton/rust/snapshots, r=brson

Time for a visit from the snapshot fairy!
Upgrade libuv to fix a leak on OSX

I haven't landed this fix upstream just yet, but it's opened as
joyent/libuv#1048. For now, I've locally merged it into my fork, and I've
upgraded our repo to point to the new revision.

Closes #11027
auto merge of #11038 : alexcrichton/rust/fix-osx-leak, r=cmr

I haven't landed this fix upstream just yet, but it's opened as
joyent/libuv#1048. For now, I've locally merged it into my fork, and I've
upgraded our repo to point to the new revision.

Closes #11027
auto merge of #11065 : huonw/rust/slice-chars-example, r=cmr
Generalize item_span into node_span, which works on more types.

Signed-off-by: Edward Z. Yang <ezyang@cs.stanford.edu>
std::vec: use some unsafe code to optimise `remove`.

Also, add `.remove_opt` and replace `.unshift` with `.remove(0)`. The
code size reduction seem to compensate for not having the optimised
special cases.

This makes the included benchmark more than 3 times faster.
auto merge of #11061 : huonw/rust/opt-unsafe-vec, r=alexcrichton

Before:

```
test vec::bench::random_inserts                     ... bench:     15025 ns/iter (+/- 409)
test vec::bench::random_removes                     ... bench:     16063 ns/iter (+/- 276)
```

After:

```
test vec::bench::random_inserts                     ... bench:      5257 ns/iter (+/- 321)
test vec::bench::random_removes                     ... bench:      4980 ns/iter (+/- 94)
```
std: silence warnings when compiling test.
extra: silence warnings during testing.
Remove many false positives from the ctags results

Anchoring the keyword as the first non-whitespace on a line may mean
that the occasional genuine-but-unconventionally-formatted tag is
missed, but it avoids a large number of false positives.

I changed the type descriptive texts about a bit too. That part's purely
cosmetic.

I also changed the ignored file list to use a filename matching the make
rule, `TAGS.vi` instead of `TAGS.vim`.
Rename pkgid to crate_id

Closes #11035
Add some things to inspect crate-id's
auto merge of #11041 : cmr/rust/pkgid_changes, r=cmr,metajack
rustc: Handle `#[link(name = "")]` error
mklldeps.py: Ignore extra whitespaces of argument
auto merge of #11070 : ezyang/rust/better-errors, r=alexcrichton

On the advice of @huonw, I've just replaced item_span outright.

Signed-off-by: Edward Z. Yang <ezyang@cs.stanford.edu>
auto merge of #11072 : chris-morgan/rust/ctags-tweaks, r=cmr

Anchoring the keyword as the first non-whitespace on a line may mean
that the occasional genuine-but-unconventionally-formatted tag is
missed, but it avoids a large number of false positives.

I changed the type descriptive texts about a bit too. That part's purely
cosmetic.

I also changed the ignored file list to use a filename matching the make
rule, `TAGS.vi` instead of `TAGS.vim`.