return value/use extra::test::black_box in benchmarks
extra: Capture stdout/stderr of tests by default

When tests fail, their stdout and stderr is printed as part of the summary, but
this helps suppress failure messages from #[should_fail] tests and generally
clean up the output of the test runner.
Don't copy &Trait and &mut Trait to temporaries for every call.
Ensure an error is raised on infinite recursion
Add function doc comments for extra::url::*
Removed libextra dependency from libsyntax.
Add test for #8860
Expand ItemDecorator extensions in all contexts

Now that fold_item can return multiple items, this is pretty trivial. It
also recursively expands generated items so ItemDecorators can generate
items that are tagged with ItemDecorators!

Closes #4913
Removed the obsolete ast::CallSugar (previously used by `do`).
Invoke gcc with -nodefaultlibs

This will hopefully bring us closer to #11937. We're still using gcc's idea of
"startup files", but this should prevent us from leaking in dependencies that we
don't quite want (libgcc for example once compiler-rt is what we use).
auto merge of #12205 : alexcrichton/rust/nodefaultlibs, r=brson

This will hopefully bring us closer to #11937. We're still using gcc's idea of
"startup files", but this should prevent us from leaking in dependencies that we
don't quite want (libgcc for example once compiler-rt is what we use).
Add MKFILE_DEPS to compiler-rt target

Currently when you run `make -jN` it's likely that you'll remove compiler-rt and
then it won't get cp'd back into the right place. I believe the reason for this
is that the compiler-rt library target never got updated so make decided it
never needed to copy the files back into place. The files were all there at the
beginning of `make`, but then we may clean out the stage0 versions if we unzip
the snapshot again.
rustdoc: Strip impls of stripped private types

In strip-private, also strip impls of traits for private types. This
fixes the search index so searching for "drop", "eq", etc doesn't throw
an exception.
rustdoc: Strip impls of traits on #[doc(hidden)] types

In the strip-hidden pass, record all types that were stripped, and make
a second pass stripping all impls of traits for these types.
tutorial: stronger wording in build instructions
Test fixes and rebase conflicts from rollups

PRs closed as part of this:

Closes #12212 r=alexcrichton
Closes #12215 r=brson
Closes #12246 r=pcwalton
Closes #12247 r=cmr
Closes #12251 r=brson
Closes #12255 r=alexcrichton
Closes #12257 r=alexcrichton
Closes #12258 r=huonw
Closes #12259 r=huonw
Closes #12263 r=kballard
Closes #12269 r=alexcrichton
Update vim syntax for extern crate
Add CheckedDiv to vim syntax
auto merge of #12267 : alexcrichton/rust/rollup, r=alexcrichton

The last commit has the closed PRs
Update restrictions on rustdoc source rendering

The std macros used to be injected with a filename of "<std-macros>", but macros
are now injected with a filename of "<{} macros>" where `{}` is filled in with
the crate name. This updates rustdoc to understand this new system so it'll
render source more frequently.