rustc: Get LLVM error message safely

On Windows, `LLVMRustGetLastError()` may return non-utf8 mojibake string
if system uses non-English locale. It caused ICE when llvm fails.
This patch doesn't fix the real problem, but just make rustc not die.
rustdoc: Don't escape contents of headers

Turns out sundown has already escaped this content for us, so there's no need
for us to escape it again.

Closes #12736
test: Add some tests for closed issues

Closes #6738
Closes #7061
Closes #7899
Closes #9719
Closes #10028
Closes #10228
Closes #10401
Closes #11192
Closes #11508
Closes #11529
Closes #11873
Closes #11925
auto merge of #12732 : klutzy/rust/this-is-windows, r=alexcrichton

On Windows, `LLVMRustGetLastError()` may return non-utf8 mojibake string
if system uses non-English locale. It caused ICE when llvm fails.
This patch doesn't fix the real problem, but just make rustc not die.
auto merge of #12737 : alexcrichton/rust/issue-12736, r=brson

Turns out sundown has already escaped this content for us, so there's no need
for us to escape it again.

Closes #12736
auto merge of #12738 : alexcrichton/rust/needstest, r=brson,just

Closes #6738
Closes #7061
Closes #7899
Closes #9719
Closes #10028
Closes #10228
Closes #10401
Closes #11192
Closes #11508
Closes #11529
Closes #11873
Closes #11925
rustc: Move to FNV hashing for node/def ids

This leverages the new hashing framework and hashmap implementation to provide a
much speedier hashing algorithm for node ids and def ids. The hash algorithm
used is currentl FNV hashing, but it's quite easy to swap out.

I originally implemented hashing as the identity function, but this actually
ended up in slowing down rustc compiling libstd from 8s to 13s. I would suspect
that this is a result of a large number of collisions.

With FNV hashing, we get these timings (compiling with --no-trans, in seconds):

|           |  before  |  after  |
|-----------|---------:|--------:|
| libstd    |   8.324  |  6.703  |
| stdtest   |  47.674  | 46.857  |
| libsyntax |   9.918  |  8.400  |
collections: Correct with_capacity_and_hasher

The arguments were accidentally swapped in the wrong order.

Closes #12743
syntax: Conditionally deriving(Hash) with Writers

If #[feature(default_type_parameters)] is enabled for a crate, then
deriving(Hash) will expand with Hash<W: Writer> instead of Hash<SipState> so
more hash algorithms can be used.
auto merge of #12635 : alexcrichton/rust/speedy-hash, r=brson

This leverages the new hashing framework and hashmap implementation to provide a
much speedier hashing algorithm for node ids and def ids. The hash algorithm
used is currentl FNV hashing, but it's quite easy to swap out.

I originally implemented hashing as the identity function, but this actually
ended up in slowing down rustc compiling libstd from 8s to 13s. I would suspect
that this is a result of a large number of collisions.

With FNV hashing, we get these timings (compiling with --no-trans, in seconds):

|           |  before  |  after  |
|-----------|---------:|--------:|
| libstd    |   8.324  |  6.703  |
| stdtest   |  47.674  | 46.857  |
| libsyntax |   9.918  |  8.400  |
auto merge of #12746 : alexcrichton/rust/issue-12743, r=brson

The arguments were accidentally swapped in the wrong order.

Closes #12743
std: stop `vec!()` warning about unused mutability.

If no arguments are given to `vec!` then no pushes are emitted and
so the compiler (rightly) complains that the mutability of `temp` is
never used.

This behaviour is rather annoying for users.
Explicitly write down 0.1 release date in RELEASES.txt, to confirm Rust's birthday.
change FVN hash function to the FVN-1a variant
auto merge of #12749 : tedhorst/rust/master, r=huonw

Minor change to the FVN hashing function based on recommendation on: http://en.wikipedia.org/wiki/Fowler_Noll_Vo_hash

cc @alexcrichton
rename ast::ViewItemExternMod to ast::ViewItemExternCrate, and clean::ExternMod to clean::ExternCrate
auto merge of #12750 : liigo/rust/De-extern-mod, r=alexcrichton

rename ast::ViewItemExternMod to ast::ViewItemExternCrate
rename rustdoc::clean::ExternMod to rustdoc::clean::ExternCrate
because `extern mod` is out.
auto merge of #12753 : huonw/rust/vec-macro, r=cmr

If no arguments are given to `vec!` then no pushes are emitted and
so the compiler (rightly) complains that the mutability of `temp` is
never used.

This behaviour is rather annoying for users.
Index cross-mod type definition and implementation properly in rustdoc

A structure's definition and implementation may be cross-module. If the
implementing module is parsed before defining module, the fully
qualified name of the structure won't be present for the implementation
to use when being indexed. So caches such 'orphan' implementation and
indexes it at the end of crate parsing.

Closes #10284.
auto merge of #12752 : edwardw/rust/rdoc, r=alexcrichton

A structure's definition and implementation may be cross-module. If the
implementing module is parsed before defining module, the fully
qualified name of the structure won't be present for the implementation
to use when being indexed. So caches such 'orphan' implementation and
indexes it at the end of crate parsing.

Closes #10284.