Rollup of 7 pull requests

[Centril]

Successful merges:

• Document std::fs::File close behavior ignoring errors #59470 (Document std::fs::File close behavior ignoring errors)
• update miri #59555 (update miri)
• update stdsimd #59556 (update stdsimd)
• as_deref() and as_deref_mut() impls #59628 (as_deref() and as_deref_mut() impls)
• Never return uninhabited values at all #59639 (Never return uninhabited values at all)
• Add description for -Os and -Oz in rustc.1 #59685 (Add description for -Os and -Oz in rustc.1)
• Temporarily disable stack probing for gnux32. #59686 (Temporarily disable stack probing for gnux32.)

Failed merges:

r? @ghost

[Centril]

@bors r+ p=7

[bors]

📌 Commit 03a6ae6 has been approved by Centril

[bors]

⌛ Testing commit 03a6ae6 with merge 301460c95ccbb910a34ca864cdfbb6157c7ecda8...

[bors]

💔 Test failed - checks-travis

[rust-highfive]

The job x86_64-gnu-tools of your PR failed on Travis (raw log). Through arcane magic we have determined that the following fragments from the build log may contain information about the problem.

Click to expand the log.

[01:31:36] [RUSTC-TIMING] miri test:false 86.660
[01:31:37] error[E0599]: no method named `deref` found for type `std::option::Option<std::string::String>` in the current scope
[01:31:37]    --> src/tools/miri/src/bin/cargo-miri.rs:296:60
[01:31:37]     |
[01:31:37] 296 |     let (subcommand, skip) = match std::env::args().nth(2).deref() {
[01:31:37] 
[01:31:37] error: aborting due to previous error
[01:31:37] 
[01:31:37] For more information about this error, try `rustc --explain E0599`.
---
[01:31:51] This PR updated 'src/tools/miri', verifying if status is 'test-pass'...
[01:31:51] 
[01:31:51] ⚠️ We detected that this PR updated 'miri', but its tests failed.
[01:31:51] 
[01:31:51] If you do intend to update 'miri', please check the error messages above and
[01:31:51] commit another update.
[01:31:51] 
[01:31:51] If you do NOT intend to update 'miri', please ensure you did not accidentally
[01:31:51] change the submodule at 'src/tools/miri'. You may ask your reviewer for the
[01:31:51] proper steps.
The command "stamp sh -x -c "$RUN_SCRIPT"" exited with 3.
travis_time:start:143c473c
$ date && (curl -fs --head https://google.com | grep ^Date: | sed 's/Date: //g' || true)
Thu Apr  4 12:45:54 UTC 2019
---
travis_time:end:2a853a1c:start=1554381955758529168,finish=1554381955770707674,duration=12178506
travis_fold:end:after_failure.3
travis_fold:start:after_failure.4
travis_time:start:0130c5f9
$ ln -s . checkout && for CORE in obj/cores/core.*; do EXE=$(echo $CORE | sed 's|obj/cores/core\.[0-9]*\.!checkout!\(.*\)|\1|;y|!|/|'); if [ -f "$EXE" ]; then printf travis_fold":start:crashlog\n\033[31;1m%s\033[0m\n" "$CORE"; gdb --batch -q -c "$CORE" "$EXE" -iex 'set auto-load off' -iex 'dir src/' -iex 'set sysroot .' -ex bt -ex q; echo travis_fold":"end:crashlog; fi; done || true
travis_fold:end:after_failure.4
travis_fold:start:after_failure.5
travis_time:start:146fcf07
travis_time:start:146fcf07
$ cat ./obj/build/x86_64-unknown-linux-gnu/native/asan/build/lib/asan/clang_rt.asan-dynamic-i386.vers || true
cat: ./obj/build/x86_64-unknown-linux-gnu/native/asan/build/lib/asan/clang_rt.asan-dynamic-i386.vers: No such file or directory
travis_fold:end:after_failure.5
travis_fold:start:after_failure.6
travis_time:start:09fd8528
$ dmesg | grep -i kill

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