Update cargo

6 commits in 95b45eca19ac785263fed98ecefe540bb47337ac..0e35bd8af0ec72d3225c4819b330b94628f0e9d0
2019-03-06 19:24:30 +0000 to 2019-03-13 06:52:51 +0000
- Make `hg` optional for tests. (rust-lang/cargo#6739)
- Fingerprint build script deps only for path packages. (rust-lang/cargo#6734)
- Add --quiet option for `cargo test` (rust-lang/cargo#6358)
- .gitignore should end with a newline. (rust-lang/cargo#6732)
- Emit warning on misspelled environment variables (rust-lang/cargo#6694)
- Update glob requirement from 0.2.11 to 0.3.0 (rust-lang/cargo#6724)

resolve: Simplify import resolution for mixed 2015/2018 edition mode

Non-controversial part of https://github.com/rust-lang/rust/pull/57745.

Before:

| Local edition (per-span) | Global edition (--edition) | Imports (`use foo;`)                                 | Absolute paths (`::foo`)                                 |
| ------------- |----------------|-----------------------------------------|------------------------------------------------|
| 2018          | Any            | Uniform                                 | Extern prelude                                 |
| 2015          | 2015           | Crate-relative                          | Crate-relative                                 |
| 2015          | 2018           | Crate-relative with fallback to Uniform (future-proofed to error if the result is not Crate-relative or from Extern prelude) | Crate-relative with fallback to Extern prelude |

After:

| Local edition (per-span) | Global edition (--edition) | Imports (`use foo;`)                                 | Absolute paths (`::foo`)                                 |
| ------------- |----------------|-----------------------------------------|------------------------------------------------|
| 2018          | Any            | Uniform                                 | Extern prelude                                 |
| 2015          | 2015           | Crate-relative                          | Crate-relative                                 |
| 2015          | 2018           | Crate-relative with fallback to Extern prelude | Crate-relative with fallback to Extern prelude |

I.e. only the behavior of the mixed local-2015-global-2018 mode is changed.
This mixed mode has two goals:
- Address regressions from https://github.com/rust-lang/rust/pull/56053#issuecomment-440826397.
Both "before" and "after" variants address those regressions.
- Be retrofit-able to "full 2015" edition (https://github.com/rust-lang/rust/pull/57745).
Any more complex fallback scheme (with more candidates) than "Crate-relative with fallback to Extern prelude" will give more regressions than https://github.com/rust-lang/rust/pull/57745#issuecomment-455855089 and is therefore less retrofit-able while also being, well, more complex.
So, we can settle on "Crate-relative with fallback to Extern prelude".

(I'll hopefully proceed with https://github.com/rust-lang/rust/pull/57745 after mid-February.)

r? @Centril

Use derive macro for HashStable

Blocked on https://github.com/rust-lang/rust/pull/56795

Rollup of 16 pull requests

Successful merges:

 - #58829 (librustc_interface: Update scoped-tls to 1.0)
 - #58876 (Parse lifetimes that start with a number and give specific error)
 - #58908 (Update rand version)
 - #58998 (Fix documentation of from_ne_bytes and from_le_bytes)
 - #59056 (Use lifetime contravariance to elide more lifetimes in core+alloc+std)
 - #59057 (Standardize `Range*` documentation)
 - #59080 (Fix incorrect links in librustc_codegen_llvm documentation)
 - #59083 (Fix #54822 and associated faulty tests)
 - #59093 (Remove precompute_in_scope_traits_hashes)
 - #59101 (Reduces Code Repetitions like `!n >> amt`)
 - #59121 (impl FromIterator for Result: Use assert_eq! instead of assert!)
 - #59124 (Replace assert with assert_eq)
 - #59129 (Visit impl Trait for dead_code lint)
 - #59130 (Note that NonNull does not launder shared references for mutation)
 - #59132 (ignore higher-ranked object bound conditions created by WF)
 - #59138 (Simplify Iterator::{min, max})

Failed merges:

r? @ghost

Simplify Iterator::{min, max}

This PR simplifies the `select_fold1` helper method used to implmement `Iterator::{min, min_by, min_by_key, max, max_by, max_by_key}` by removing the projection argument, which was only used by the implementations of `min_by_key` and `max_by_key`.

I also added tests to ensure that the stability as mentioned in the comments of `min` and `max` is preserved, and fixed the `iter::{bench_max, bench_max_by_key}` benchmarks which the compiler presumably was able to collapse into closed-form expressions. None of the benchmark results were impacted, I suspect their generated assembly didn't change.

ignore higher-ranked object bound conditions created by WF

In the `issue-53548` test added in this PR, the `Box<dyn Trait>` type is expanded to `Box<dyn Trait + 'static>`, but the generator "witness" that results is `for<'r> { Box<dyn Trait + 'r> }`. The WF code was encountering an ICE (when debug-assertions were enabled) and an unexpected compilation error (without debug-asserions) when trying to process this `'r` region bound. In particular, to be WF, the region bound must meet the requirements of the trait, and hence we got `for<'r> { 'r: 'static }`. This would ICE because the `Binder` constructor we were using was assering that no higher-ranked regions were involved (because the WF code is supposed to skip those). The error (if debug-asserions were disabled) came because we obviously cannot prove that `'r: 'static` for any region `'r`.  Pursuant with
our "lazy WF" strategy for higher-ranked regions, the fix is not to require that `for<'r> { 'r: 'static }` holds (this is also analogous to what we would do for higher-ranked regions appearing within the trait in other positions).

Fixes #53548

r? @pnkfelix

Note that NonNull does not launder shared references for mutation

See https://users.rust-lang.org/t/relative-pointer-an-abstraction-to-build-movable-self-referential-types/26186/6

Visit impl Trait for dead_code lint

Fix #59085.

Replace assert with assert_eq

Use `assert_eq!` instead of `assert!` for the tests

impl FromIterator for Result: Use assert_eq! instead of assert!

Reduces Code Repetitions like `!n >> amt`

Fixes #49937 .
This PR contains defining a function which operates bit inversion and reducing bit operation like `!0u128 >> (128 - size.bits())`.

Remove precompute_in_scope_traits_hashes

r? @michaelwoerister

Fix #54822 and associated faulty tests

Type checking associated constants can require trait bounds, but an empty
parameter environment was provided to the trait solver.  Providing an
appropriate parameter environment seems to fix #54822 and also make one of the
cases in src/test/ui/nll/trait-associated-constant.rs that should compile
successfully do so.  It also (slightly) improves the error message in
src/test/ui/associated-const/associated-const-generic-obligations.rs

Fix incorrect links in librustc_codegen_llvm documentation

Standardize `Range*` documentation

This updates the final example in the documentation for the types
`Range`, `RangeFrom`, `RangeFull`, `RangeInclusive`, `RangeTo`,
`RangeToInclusive`.

Use lifetime contravariance to elide more lifetimes in core+alloc+std

Sample:
```diff
-    impl<'a, 'b, A: ?Sized, B: ?Sized> PartialEq<&'b mut B> for &'a mut A where A: PartialEq<B> {
+    impl<A: ?Sized, B: ?Sized> PartialEq<&mut B> for &mut A where A: PartialEq<B> {
         #[inline]
-        fn eq(&self, other: &&'b mut B) -> bool { PartialEq::eq(*self, *other) }
+        fn eq(&self, other: &&mut B) -> bool { PartialEq::eq(*self, *other) }
         #[inline]
-        fn ne(&self, other: &&'b mut B) -> bool { PartialEq::ne(*self, *other) }
+        fn ne(&self, other: &&mut B) -> bool { PartialEq::ne(*self, *other) }
     }
```

[I didn't know this worked](https://internals.rust-lang.org/t/why-can-you-use-different-unconstrained-lifetimes-to-implement-traits/9544/2?u=scottmcm) until recently, but since defining methods contravariantly in their lifetimes this way has worked back to Rust 1.0, we might as well take advantage of combining it with IHLE.

Fix documentation of from_ne_bytes and from_le_bytes

Copypasta mistake, the documentation of `from_ne_bytes` and `from_le_bytes` used the big-endian variant in the example snippets.

Update rand version

cc: #57724

r? @scottmcm

Parse lifetimes that start with a number and give specific error

Fix #58786.

librustc_interface: Update scoped-tls to 1.0

Done previously as a part of https://github.com/rust-lang/rust/pull/58748.

r? @Zoxc

Add tests for several E-needstest issues

This PR adds a number of tests for various `E-needstest` errors. These tend to have been left open for a long time and seem unlikely to be closed otherwise.

Closes https://github.com/rust-lang/rust/issues/10876.
Closes https://github.com/rust-lang/rust/issues/26448.
Closes https://github.com/rust-lang/rust/issues/26577.
Closes https://github.com/rust-lang/rust/issues/26619.
Closes https://github.com/rust-lang/rust/issues/27054.
Closes https://github.com/rust-lang/rust/issues/44127.
Closes https://github.com/rust-lang/rust/issues/44255.
Closes https://github.com/rust-lang/rust/issues/55731.
Closes https://github.com/rust-lang/rust/issues/57781.

Expand docs for `TryFrom` and `TryInto`.

The examples are still lacking for now, both for module docs and for methods/impl's.  Will be adding those in further pushes.

Should hopefully resolve the doc concern in #33417 when finished?

These still fail on some architectures.