Add a copy-on-write container.
Added Freeze trait to CowArc
Add @Spell clusters to Vim syntax file

Add @Spell clusters to Vim syntax highlighting file to do spell checking
only inside comments and strings
added empty() to Peekable
Introduced a chapter that describes how to perform callbacks from C to Rust
Further details on channel idea
Removed remnants of `@mut` and `~mut` from comments and the type system.
Support linking of rlib files in rustpkg
Fix indention
Add inline attributes documentation.

Closes #7959.
auto merge of #11491 : wting/rust/wting_7959_document_inline_attributes, r=alexcrichton

Closes #7959.
more backticks
auto merge of #11495 : kud1ing/rust/backticks, r=huonw
Update guide-ffi.md

Simplified the first examples to demonstrate callbacks without other threads involved and shortened the elaboration about async callbacks.
extra::ebml: Make reader::Res public

Since reader::vuint_at() returns a result of type reader::Res it makes sense
to make it public.

Due to rust's current behavior of externally referenced private structures,
https://github.com/mozilla/rust/issues/10573, you could still use the result and
assign it to a variable if you let the compiler do the type assignment,
but you could not explicitly annotate a variable to hold a reader::Res.
extra::ebml: Add unit test for vuint_at()
Don't overwrite the options.output value from build_session_options
Mark allowed dead code and lang items as live

Dead code pass now explicitly checks for `#[allow(dead_code)]` and
`#[lang=".."]` attributes on items and marks them as live if they have
those attributes. The former is done so that if we want to suppress
warnings for a group of dead functions, we only have to annotate the
"root" of the call chain.
auto merge of #11471 : ktt3ja/rust/issue-11380, r=alexcrichton

Dead code pass now explicitly checks for `#[allow(dead_code)]` and
`#[lang=".."]` attributes on items and marks them as live if they have
those attributes. The former is done so that if we want to suppress
warnings for a group of dead functions, we only have to annotate the
"root" of the call chain.

Close #11380 and #11440.
ebml::extra: Optimize reader::vuint_at()

Use a lookup table, SHIFT_MASK_TABLE, that for every possible four
bit prefix holds the number of times the value should be right shifted and what
the right shifted value should be masked with. This way we can get rid of the
branches which in my testing gives approximately a 2x speedup.