Register new snapshots
Update submodules to point to rust-lang repos
Add eof to MemReader and BufReader

It's easy to figure out and useful as a sanity check sometimes.
auto merge of #11418 : alexcrichton/rust/snapshots, r=cmr
Fix ICE on const of nullable enum with fields in null case.

That is, if you have an enum type that is subject to the nullable
pointer optimization, but the null variant has a nonzero number of
fields, and you declare a static whose value is of that variant, then
that used to be an ICE but this change fixes it.
auto merge of #11433 : brson/rust/minorstylefixes, r=alexcrichton
auto merge of #11436 : alexcrichton/rust/update-forks, r=huonw

We're not moving everything just yet, but it's good to start somewhere!
auto merge of #11437 : sfackler/rust/mem-eof, r=alexcrichton

It's easy to figure out and useful as a sanity check sometimes.
auto merge of #11441 : jld/rust/enum-nullable-const-null-with-fields, r=alexcrichton

That is, if you have an enum type that is subject to the nullable
pointer optimization, but the null variant has a nonzero number of
fields, and you declare a static whose value is of that variant, then
that used to be an ICE but this change fixes it.
"As long an iterator" => "As long as an iterator"
Fix #11421
auto merge of #11451 : kud1ing/rust/patch-1, r=cmr
auto merge of #11452 : derekchiang/rust/fix-11421, r=cmr

Closes #11421.  A pretty trivial fix.
Improve invalid operator assignment handling.
auto merge of #11449 : rcatolino/rust/assign-binop-handling, r=alexcrichton

So far the following code
```
struct Foo;

fn main() {
  let mut t = Foo;
  let ref b = Foo;
  a += *b;
}
```
errors with 
```
test.rs:15:3: 13:11 error: binary operation + cannot be applied to type `Foo`
test.rs:15   *a += *b;
```
Since assignment-operators are no longer expanded to ```left = left OP right``` but are independents operators it should be 
```
test.rs:15:3: 13:11 error: binary operation += cannot be applied to type `Foo`
test.rs:15   *a += *b;
```
to make it clear that implementing Add for Foo is not gonna work. (cf issues #11143, #11344)

Besides that, we also need to typecheck the rhs expression even if the operator has no implementation, or we end up with unknown types for the nodes of the rhs and an ICE later on while resolving types. (once again cf #11143 and #11344).

This probably would get fixed with #5992, but in the meantime it's a confusing error to stumble upon.
@pcwalton, you wrote the original code, what do you think?
(closes #11143 and #11344)
Bump version to 0.10-pre
Downgrade std back to 0.9 sice std inject is preventing the upgrade
rustc: Stop injecting crate version numbers in std_inject

The snapshot version injection is preventing us from upgrading to
0.10-pre, so I'm removing the version injection. Since our version-foo
is probably not good enough to allow multiple versions of these libs to
coexist side-by-side anyway, I think this will have minimal impact.