[std::path] Rename .container_as_str_opt() to .container_as_str(), drop the old .container_as_str() behavior

* Stop using hardcoded numbers that have to all get updated when something changes (inevitable errors and rebase conflicts) as well as removes some unneeded -Z options (obsoleted over time).
* Remove `std::rt::borrowck`

This hasn't been in use since `@mut` was removed

* borrowck_note_pure - unused
* borrowck_note_loan - unused
* no_debug_borrows - unused
* lint_llvm - equivalent to -Z no-prepopulate-passes + --llvm-passes lint

Instead use a macro and generate them!

The parens in `if (true) {}` are not necessary, so we'll warn about them.

cc #3070 and #11432

The parens in `if (true) {}` are not not necessary, so we'll warn about
them.

Upgrade the version to 0.10-pre

It previously missed anything in an inner module.

Found out about `file!` today from o11c in IRC.

The included test case would essentially never finish compiling without this
patch. It recursies twice at every ExprParen meaning that the branching factor
is 2^n

The included test case will take so long to parse on the old compiler that it'll
surely never let this crop up again.

Upgrade the version to 0.10-pre

I wrote a chapter for the FFI tutorial that describes how to perform callbacks from C code to Rust and gives some hints about what to consider and synchronization.

I just needed that for my own wrapper and thought it would be helpful for others.

Closes #11647

They need to read the metadata of cross-compiled crates, so the pretty things
need to have the right target.

They need to read the metadata of cross-compiled crates, so the pretty things
need to have the right target.

The included test case would essentially never finish compiling without this
patch. It recursies twice at every ExprParen meaning that the branching factor
is 2^n

The included test case will take so long to parse on the old compiler that it'll
surely never let this crop up again.

This means we can purge even more C from src/rt!

This means we can purge even more C from src/rt!

Closes #11647

`Zero` and `One` have precise definitions in mathematics as the identities of the `Add` and `Mul` operations respectively. As such, types that implement these identities are now also required to implement their respective operator traits. This should reduce their misuse whilst still enabling them to be used in generalized algebraic structures (not just numbers). Existing usages of `#[deriving(Zero)]` in client code could break under these new rules, but this is probably a sign that they should have been using something like `#[deriving(Default)]` in the first place.

For more information regarding the mathematical definitions of the additive and multiplicative identities, see the following Wikipedia articles:

- http://wikipedia.org/wiki/Additive_identity
- http://wikipedia.org/wiki/Multiplicative_identity

Note that for floating point numbers the laws specified in the doc comments of `Zero::zero` and `One::one` may not always hold. This is true however for many other traits currently implemented by floating point numbers. What traits floating point numbers should and should not implement is an open question that is beyond the scope of this pull request.

The implementation of `std::num::pow` has been made more succinct and no longer requires `Clone`. The coverage of the associated unit test has also been increased to test for more combinations of bases, exponents, and expected results.

It previously missed anything in an inner module.

It was the only span_* missing.

Previously, they were treated like ~[] and &[] (which can have length
0), but fixed length vectors are fixed length, i.e. we know at compile
time if it's possible to have length zero (which is only for [T, .. 0]).

Fixes #11659.

The provided span isn't used in all cases (namely primitives).

We can use a secondary macro to calculate the count from the information
we're already having to pass to the lang items macro.