rt: Set the stack depth limit to 1GB. Abort on error.

People hit the recursion depth limit too often, it's not possible
to unwind reliably from out-of-stack.

Issues #3555, #3695
core: Move mkdir_recursive from rustpkg into core::os

mkdir_recursive creates a directory as well as any of its
parent directories that don't exist already. Seems like a useful
thing to have in core.
auto merge of #6081 : brson/rust/out-of-stack, r=thestinger

People hit the recursion depth limit too often, it's not possible
to unwind reliably from out-of-stack.

Issues #3555, #3695
auto merge of #6082 : catamorphism/rust/mkdir_recursive, r=brson

r? @brson mkdir_recursive creates a directory as well as any of its
parent directories that don't exist already. Seems like a useful
thing to have in core.

(Or r? anyone who gets to it first.)
only use #[no_core] in libcore
auto merge of #6075 : thestinger/rust/no-no_core, r=brson

core injection works fine now
rand: Fix infinite recursion

`self` has type `&@Rand`, so `*self` will be of type `@Rand` which causes
this same impl to be called again.
auto merge of #6097 : Blei/rust/fix-rand, r=pnkfelix

`self` has type `&@Rand`, so `*self` will be of type `@Rand` which causes
this same impl to be called again.

Fixes #6061
Revert "libcore: remove unnecessary deref"

This reverts commit 9860fe10a19cc4997e58861df905f8dbe4de3c5b.
librustc: Remove `ptr::addr_of`.
librustc: Implement `reinterpret_cast` in terms of `transmute`.
librustc: Rename `reinterpret_cast` to `transmute_copy` and remove the intrinsic
librustc: Remove the legacy mode in the type visitor intrinsic.
libfuzzer: De-mode the fuzzer.
test: Remove #[legacy_modes] from the test suite.
librustc: Make `&fn` by-copy by default and remove the mode from `frame_address`.
librustc: Remove the concept of modes from the compiler.

This commit does not remove `ty::arg`, although that should be
possible to do now.
test: Fix tests.
librustc: Change labels to use the lifetime notation `'`.
librustc: Forbid type implementations on typedefs.