rt: don't save and restore xmm/regs in __morestack.
fixes stated grammar for block comments, by adding Kleene '+' in two places.

Closes #1588
fix another subtle bug in comment regex
added defn of non_slash_or_star
libsyntax: Don't allow `impl (Trait) for Type` (with the parentheses).
testsuite: Update and un-xfail test for #4335
testsuite: Add test for #4333
libcore: Add `print` and `println` to the prelude
testsuite: Add test case for #4325
core: Inline mallocing wrapper functions

As far as I can tell, this doesn't make rust compile any
faster, but it does at least remove one level of indirection
on malloc, which might help speed up some operations.
std: change Decoder::read_option to return a generic type

This allows read_option to be used with a custom option type instead
of just core::Option.
Fix warning about unused imports in import lists

Before, if anything in a list was used, the entire list was considered to be
used. This corrects this and also warns on a span of the actual unused import
instead of the entire list.
Removing unused imports
auto merge of #5616 : pcwalton/rust/parenthesized-trait, r=brson

r? @brson
libcore: language change minor fix for ARM & MIPS
auto merge of #5617 : catamorphism/rust/issue-4335, r=catamorphism
auto merge of #5618 : pcwalton/rust/print-in-prelude, r=brson

r? @brson
auto merge of #5619 : catamorphism/rust/issue-4333, r=catamorphism
auto merge of #5620 : catamorphism/rust/issue-4325, r=catamorphism
auto merge of #5622 : yichoi/rust/pull-0329, r=catamorphism

libcore: language change minor fix for ARM & MIPS

fix context.rs