Rollup of 9 pull requests

[arielb1]

• Successful merges: Adds rust-windbg.cmd script #39983, Check privacy of trait items in all contexts #41332, Add bootstrap support for android #41370, Specify behavior of write_all for ErrorKind::Interrupted errors #41442, Add internal accessor methods to io::{Chain, Take}. #41463, Step::replace_one should put a one, not a zero (Issue #41492) #41493, use the word 'length' in Vec::len's docs #41500, Fix a copy-paste error in Instant::sub_duration #41518, Clean up TcpStream example #41526
• Failed merges:

[rust-highfive]

r? @sfackler

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[arielb1]

@bors r+ p=10

[bors]

📌 Commit a1a19e6 has been approved by arielb1

[bors]

⌛ Testing commit a1a19e6 with merge 4e30e41...

[bors]

💔 Test failed - status-travis

[aidanhs]

Seems like a legit failure

[00:37:25] ---- [compile-fail] compile-fail/trait-item-privacy.rs stdout ----
[00:37:25] 	
[00:37:25] error: /checkout/src/test/compile-fail/trait-item-privacy.rs:86: unexpected "error": '86:19: 86:21: the trait `method::C` cannot be made into an object [E0038]'
[00:37:25] 
[00:37:25] error: /checkout/src/test/compile-fail/trait-item-privacy.rs:88: unexpected "error": '88:7: 88:8: the trait bound `method::C: method::B` is not satisfied [E0277]'
[...]