fix the core-map benchmark's descending range
remove sty_by_ref, though traces still remain due to dtors
Simplify and remove unnecessary use of ast_map
Autoref the argument to the index operator (#4920)
testsuite: Add various test cases

Some are xfailed, some not, some existing ones get un-xfailed.
Oh, cool, I xfailed the wrong test, neat
testsuite: more `pub fn main`
another pub fn for check-fast
Fix pretty-printer test failure by carrying the bound lifetime names through
the types.  Initially I thought it would be necessary to thread this data
through not only the AST but the types themselves, but then I remembered that
the pretty printer only cares about the AST.  Regardless, I have elected to
leave the changes to the types intact since they will eventually be needed.  I
left a few FIXMEs where it didn't seem worth finishing up since the code wasn't
crucial yet.
auto merge of #5558 : nikomatsakis/rust/issue-4920-autoref-index-operator, r=nikomatsakis

Per discussion on IRC.

r? @pcwalton
auto merge of #5569 : thestinger/rust/map, r=catamorphism