Also spell out that read and write operations should be retried on
`ErrorKind::Interrupted` errors.

Fixes rust-lang#38494.

Fixes rust-lang#37866

Fixes rust-lang#41514.

Resolves rust-lang#29067.

With regards to the unstable book, the reference, and the
processes involved.

Also, fix up a link by pointing to the new tracking issue rather than
the older one.

Fixes rust-lang#41285

Fixes rust-lang#33269

Fixes rust-lang#37746

Adds rust-windbg.cmd script

Adds rust-gdb/rust-lldb equivalent for windbg that loads the Rust .natvis files on start.

This change modifies the bootstrap code to add rust-windbg to bin and the .natvis files to lib/rustlib/etc.

Example usage from cmd or PowerShell:
```
rust-windbg -c "bu rs_f442289d74765418!rs::main;g" target\debug\rs.exe
```

Specify behavior of `write_all` for `ErrorKind::Interrupted` errors

Also spell out that read and write operations should be retried on
`ErrorKind::Interrupted` errors.

Fixes rust-lang#38494.

Add internal accessor methods to io::{Chain, Take}.

Resolves rust-lang#29067.

use the word 'length' in Vec::len's docs

Fixes rust-lang#37866

Fix a copy-paste error in `Instant::sub_duration`

Fixes rust-lang#41514.

Clarify the doc index

With regards to the unstable book, the reference, and the
processes involved.

Also, fix up a link by pointing to the new tracking issue rather than
the older one.

Fixes rust-lang#41285

r? @frewsxcv

Clarify "side effect" in peek's docs

Fixes rust-lang#33269

/cc @tshepang

Implement From<&mut [T]> for Vec

Fixes rust-lang#41386.

Fix up vec guarnatee around capacity

Fixes rust-lang#37746

r? @rust-lang/libs