Fix a couple places in docs where try_send wasn't changed to send_opt
std: Fix compiling on FreeBSD

Ah, the wonders of not being gated on FreeBSD...
Reduce HashMap allocations.
std: Fix demangling with middle special chars

Previously, symbols with rust escape sequences (denoted with dollar signs)
weren't demangled if the escape sequence showed up in the middle. This alters
the printing loop to look through the entire string for dollar characters.
auto merge of #13614 : cgaebel/rust/master, r=brson

We previously allocated 3x for every HashMap creation and resize. This patch reduces it to 1x.
auto merge of #13615 : alexcrichton/rust/improve-demangling, r=brson

Previously, symbols with rust escape sequences (denoted with dollar signs)
weren't demangled if the escape sequence showed up in the middle. This alters
the printing loop to look through the entire string for dollar characters.
Rewrite paragraph describing difference between try_send and send_opt
rustc: Ensure closures are "split-stack"

In upgrading LLVM, only rust functions had the "split-stack" attribute added.
This commit changes the addition of LLVM's "split-stack" attribute to *always*
occur and then we remove it sometimes if the "no_split_stack" rust attribute is
present.

Closes #13625
auto merge of #13628 : alexcrichton/rust/issue-13625, r=thestinger

In upgrading LLVM, only rust functions had the "split-stack" attribute added.
This commit changes the addition of LLVM's "split-stack" attribute to *always*
occur and then we remove it sometimes if the "no_split_stack" rust attribute is
present.

Closes #13625
auto merge of #13610 : jsanders/rust/sender-try-send-docs, r=alexcrichton

I was getting a bit confused by these and (I think) managed to track it down to fallout from #13448 and #13465.
auto merge of #13613 : alexcrichton/rust/fix-freebsd-compile, r=brson

Ah, the wonders of not being gated on FreeBSD...
serialize: Remove errant println!'s from decode
shootout-fannkuch-redux rewrite

Less bound checking and parallelisation.  Brute speed improvement
is about 15% faster.
Allow inheritance between structs.

No subtyping, no interaction with traits. Partially addresses #9912.
auto merge of #12562 : nick29581/rust/fields, r=nikomatsakis

No subtyping, no interaction with traits. Partially addresses #9912.
auto merge of #13633 : TeXitoi/rust/shootout-fannkuch-redux-rewrite, r=alexcrichton

Less bound checking and parallelisation.  Brute speed improvement
is about 15% faster.

The unsafe block improve the brute speed by about 5%.
auto merge of #13635 : richo/rust/no-output-from-serialize, r=sfackler

As an aside, it seems like a lint for libraries calling println! might be a useful thing?