Seeing `StringError("something something")` in debug output can cause
 someone to think there was an error dealing with `String`s, not that the
error type is just a string. So, remove that noise.

There is known issue where PowerShell is unreasonably slow downloading
files due to an issue with rendering the progress bar, see:

PowerShell/PowerShell#2138

That issue is fixed in PowerShell Core (available in Azure Pipelines as
pwsh.exe) but it can also be worked around by setting:

    $ProgressPreference = 'SilentlyContinue'

…ance to tag all allocations

Co-Authored-By: Mazdak Farrokhzad <twingoow@gmail.com>

error: remove StringError from Debug output

Seeing `StringError("something something")` in debug output can cause
 someone to think there was an error dealing with `String`s, not that the
error type is just a string. So, remove that noise.

For example:

```
io error: Custom { kind: InvalidData, error: StringError("corrupt data") }
```

With this change:

```
io error: Custom { kind: InvalidData, error: "corrupt data" }
```

…i-obk

Miri: give machine the chance to tag all allocations

r? @oli-obk

The Miri side of this is at rust-lang#61278.

Speed up Azure CI installing Windows dependencies

There is known issue where PowerShell is unreasonably slow downloading
files due to an issue with rendering the progress bar, see this [issue](PowerShell/PowerShell#2138)

That issue is fixed in PowerShell Core (available in Azure Pipelines as
pwsh.exe) but it can also be worked around by setting:

    $ProgressPreference = 'SilentlyContinue'

I measured downloading LLVM and it took about 220s before, 5s after, so the improvement is significant.

…e_patterns, r=Centril

Set ellipsis_inclusive_range_patterns lint to warn

Continuing rust-lang#54910, the `ellipsis_inclusive_range_patterns` lint is set to warn.

r? @Centril

…Centril

Add regression test for const generics ICE

Closes rust-lang#60879.

… r=Manishearth

Fix links in Deref documentation

Fixes rust-lang#61358.

In commonmark, the "link alias" has to be right after the link. Screenshot:

<img width="970" alt="Screenshot 2019-05-30 at 19 01 58" src="https://user-images.githubusercontent.com/3050060/58650155-3b594e00-830e-11e9-956c-4dadefa40ff0.png">

r? @Manishearth

…entril

Stabilize iter_nth_back feature

FCP done in rust-lang#56995 (comment)

Closes rust-lang#56995

r? @Centril

Fixed lifetime misspelling

…omez

Migrate some books to mdbook version 0.2

There are 3 books still using old version but they need more effort so I hope to do them in subsequent PR if I find the time.

Explicitly suggest 'type_ascription' feature

Closes: rust-lang#61325

r? @estebank