rt: don't save and restore xmm/regs in __morestack.
checkpoint
vim: disable nested comment

Since comment nesting does not work from 0.4.
vim: add rustCommentDoc
Fix a bug where calling p.destroy() on the result of calling
start_program(...) would cause a segfault when p went
out of scope due to out_file/err_file being closed twice.
Update doc-comments to reflect the current year and trait
names now being capitalized.
Change the behaviour of core::run::Program.destroy to
forcibly terminate the program (as suggested in issue #5632)
Impl cmp/num traits for BigUint, BigInt

TotalEq, TotalOrd, FromStrRadix, ToStrRadix.
cmp: derive Clone for Ordering
cmp: add Ord+TotalOrd impls for Ordering itself
auto merge of #5756 : gifnksm/rust/bigint-impl, r=thestinger

Implements TotalEq, TotalOrd, FromStrRadix, ToStrRadix for BigUint, BigInt.
vim: fix comment highlighting bug

Previous commit had a bug that a line which ends with "//" or "/*"
is not correctly highlighted.
libcore: fix overflow/underflow in range_step
Update tutorial: 1-tuples now exist
Update manual for single-element tuples
Update manual for single-element tuple types
Include definition of tuples for destructuring.

Updates the tutorial to include a simple definition for tuples in
section 4.2. Fixes #5132.
Fixed typo

Change wrong field name in "Trait Inheritance" section.
libcore: from_str_common: correctly signal failure on repeating base 2^n numbers.

A number like 0b1_1111_1111 == 511 would be parsed to Some(255u8) rather than None
by from_str_common, since 255 * 2 + 1 == 255 (mod 256) so the overflow wasn't detected.

Only applied to conversions where the radix was a power of 2, and where all digits
repeated.

Closes #5770.
libcore: from_str_common: provide option to ignore underscores.

Implement the possible improvement listed in the comment on
from_str_bytes_common.