`use` statement may introduce an crate name alias. This patch always
uses the link attrbute "name" as the crate's name when building the
crate map.
Closes#1706
Most could use the each method, but because of the hack used to
disambiguate old- and new-style loops, some had to use vec::each.
(This hack will go away soon.)
Issue #1619
- Move io, run and rand to core.
- Remove incorrect ctypes module (use libc).
- Remove os-specific modules for os and fs.
- Split fs between core::path and core::os.
As per discussion on IRC. I am about to file an RFC for further
discussion about the more general issue of whether to enforce
invariants through types, typestate, or dynamic checks, but for now,
removing the misleading name "last_unsafe".
