Stop padding metadata

This is causing maybe_get_doc to fail when called at the top level of
the metadata and doesn't appear to be needed anymore.
auto merge of #11297 : sfackler/rust/de-jank-encoder-2, r=alexcrichton

This is causing maybe_get_doc to fail when called at the top level of
the metadata and doesn't appear to be needed anymore.

A try build succeeded so this should be okay.
Make rustc's own lib directory configurable and change the default to rustlib. Fixes #3319
Do not ignore errors running llvm-config
auto merge of #11323 : sanxiyn/rust/llvm-config, r=alexcrichton

Standard error was not captured, ignoring any errors from llvm-config.
Handle EINTR throughout libnative

Closes #11214
Don't abort the process in native::start

If the main closure failed, then the `exit_code` variable would still be `None`,
and the `unwrap()` was failing (triggering a process abort). This changes the
`unwrap()` to an `unwrap_or()` in order to prevent process abort and detect when
the native task failed.
auto merge of #11304 : alexcrichton/rust/eintr, r=brson

Closes #11214
auto merge of #11313 : alexcrichton/rust/fix-native-failure, r=pcwalton
Revert "std: adjust requested stack size for thread-local storage."

This reverts commit f1b5f59287106fc511d29c425255bd343608065c.

Using a private function of a library is a bad idea: several people (on
Linux) were meeting with linking errors because of it (different/older
versions of glibc).
auto merge of #11331 : huonw/rust/revert-stack-size, r=luqmana

This reverts commit f1b5f59287106fc511d29c425255bd343608065c.

Using a private function of a library is a bad idea: several people (on
Linux) were meeting with linking errors because of it (different/older
versions of glibc).
Write up default methods for the tutorial.
Wording tweak suggested by @pcwalton.
tutorial: change `float` to `f32` since float is no longer a type.
tutorial: remove duplicate words.
tutorial: add missing line to make example build.
auto merge of #11270 : lkuper/rust/trait-docs, r=cmr

I've been wanting to explain default methods in the tutorial for ages.  While I was at it I tried to clarify some other parts of the traits section.  I'm sure this could be improved further; suggestions welcome.
librustc: ar call fix to support android cross compile on mac
librustc: move target dependent logic to back::link
librustc: add get_system_tools for target specific environment