drop some redundant Ord method implementations
partial revert of 31fa865

Ratio is generic and so might contain a non-total orderable type. It
should not use the default Ord implementation.
Make the iterator protocol more explicit

Document the fact that the iterator protocol only defines behavior up
until the first None is returned. After this point, iterators are free
to behave how they wish.

Add a new iterator adaptor Fuse<T> that modifies iterators to return
None forever if they returned None once.
Make Zip iterator short-circuit

Python's zip() short-circuits by not even querying its right-hand
iterator if the left-hand one is done. Match that behavior here by not
calling .next() on the right iterator if the left one returns None.
rustc: Change a stray error! statement to debug!
fix various warnings
rustc: capitalize types in rscope.rs
std: Add a fixme for when we add Trait::<for T>::static_method()
std: Add a file-renaming function to std::os
rustpkg: Add a not_a_workspace condition
rustpkg: Allow package directories to appear in the RUST_PATH

This commit adds a rustpkg flag, --rust-path-hack, that allows
rustpkg to *search* inside package directories if they appear in
the RUST_PATH, while *building* libraries and executables into a
different target directory.

This behavior is hidden behind a flag because I believe we only
want to support it temporarily, to make it easier to port servo to
rustpkg.

This commit also includes a fix for how rustpkg fetches sources
from git repositories -- it uses a temporary directory as the target
when invoking `git clone`, then moves that directory into the workspace
if the clone was successful. (The old behavior was that when the
`git clone` failed, the empty target directory would be left lying
around anyway.)
auto merge of #8831 : catamorphism/rust/extend_rust_path, r=catamorphism

r? @brson

@metajack requested the ability to violate the "only workspaces can be in the RUST_PATH" rule for the purpose of bootstrapping Servo without having to restructure all the directories. This patch gives rustpkg the ability to find sources if a directory in the RUST_PATH directly contains one of rustpkg's "special" files (lib.rs, main.rs, bench.rs, or test.rs), even if it's not a workspace. In this case, it puts the build artifacts in the first workspace in the RUST_PATH.

I'm not sure whether or not it's a good idea to keep this feature in rustpkg permanently. Thus, I added a flag, ```--use-rust-path-hack```, and only enabled it when the flag is set.
auto merge of #8889 : erickt/rust/cleanup, r=catamorphism

This fixes a couple minor things I've been sitting on. It cleans up some warnings, CapCases some types in librustc's rscope module, and adds a fixme.
Tweak pass management and add some more options

The only changes to the default passes is that O1 now doesn't run the inline
pass, just always-inline with lifetime intrinsics. O2 also now has a threshold
of 225 instead of 275. Otherwise the default passes being run is the same.

I've also added a few more options for configuring the pass pipeline. Namely you
can now specify arguments to LLVM directly via the `--llvm-args` command line
option which operates similarly to `--passes`. I also added the ability to turn
off pre-population of the pass manager in case you want to run *only* your own
passes.
remove several 'ne' methods
Now inline default 'ne' methods
made Eq for package_id use more standard parameter names
auto merge of #8894 : alexcrichton/rust/faster, r=thestinger

The only changes to the default passes is that O1 now doesn't run the inline
pass, just always-inline with lifetime intrinsics. O2 also now has a threshold
of 225 instead of 275. Otherwise the default passes being run is the same.

I've also added a few more options for configuring the pass pipeline. Namely you
can now specify arguments to LLVM directly via the `--llvm-args` command line
option which operates similarly to `--passes`. I also added the ability to turn
off pre-population of the pass manager in case you want to run *only* your own
passes.

I would consider this as closing #8890. I don't think that we should change the default inlining threshold because LLVM/clang will probably have chosen those numbers more carefully than we would. Regardless, here's the performance numbers from this commit:

```
$ ./x86_64-apple-darwin/stage0/bin/rustc ./gistfile1.rs --test --opt-level=3 -o before
warning: no debug symbols in executable (-arch x86_64)
$ ./before --bench

running 1 test
test bench::aes_bench_x8 ... bench: 1602 ns/iter (+/- 66) = 7990 MB/s

test result: ok. 0 passed; 0 failed; 0 ignored; 1 measured

$ ./x86_64-apple-darwin/stage1/bin/rustc ./gistfile1.rs --test --opt-level=3 -o after
warning: no debug symbols in executable (-arch x86_64)
$ ./after --bench

running 1 test
test bench::aes_bench_x8 ... bench: 2103 ns/iter (+/- 175) = 6086 MB/s

test result: ok. 0 passed; 0 failed; 0 ignored; 1 measured

$ ./x86_64-apple-darwin/stage1/bin/rustc ./gistfile1.rs --test --opt-level=3 -o after --llvm-args '-inline-threshold=225'
warning: no debug symbols in executable (-arch x86_64)
$ ./after --bench

running 1 test
test bench::aes_bench_x8 ... bench: 1600 ns/iter (+/- 71) = 8000 MB/s

test result: ok. 0 passed; 0 failed; 0 ignored; 1 measured

```
auto merge of #8862 : dcrewi/rust/drop-redundant-ord-impls, r=thestinger

If this were to break something, I would expect existing tests to catch it, and a `make check` run passes locally.
auto merge of #8896 : lightcatcher/rust/default_eq_fix, r=thestinger

Summary:
-removed "ne" methods in libstd and librustpkg
-made default "ne" be inlined
-made one of the "eq" methods in librustpkg follow more standard parameter naming convention