Updating types std::sha1::sha1 -> hash::streaming was a relatively
small change. Renaming the variables to reflect that things aren't
sha1s any more touched far more lines.
Rewrote bitv as a class that uses a 32-bit int as its representation
for bit vectors of 32 bits or less, and a vector (the old representation)
otherwise. I didn't benchmark very much, but a bit of informal benchmarking
suggested this is a win.
Closes#2341
Previously, resolve was allowing impls, traits or classes that were
nested within a fn to refer to upvars, as well as referring to type
parameters bound by the fn. Fixing this required adding a new kind of
def: def_typaram_binder, which can refer to any of an impl, trait or
class that has bound ty params. resolve uses this to enforce that
methods can refer to their parent item's type parameters, but not to
outer items' type parameters; other stages ignore it. I also made
sure that impl, trait and class methods get checked inside a
MethodRibKind thing so as to forbid upvars, and changed the definition
of MethodRibKind so that its second argument is an optional node_id
(so that required trait method signatures can be checked with a
MethodRibKind as well).
New style is allow(foo), warn(foo), deny(foo) and forbid(foo),
mirrored by -A foo, -W foo, -D foo and -F foo on command line.
These replace -W no-foo, -W foo, -W err-foo, respectively.
Forbid is new, and means "deny, and you can't override it".
It will warn you if you use the default mode for something that
is expensive to copy, and it will warn you if you use any explicit
mode other than copy. So you should migrate over to using the
default mode for most things (and borrowed pointers when you don't
want to copy) and copy mode for things you really wanted to copy.
We can't throw an exception from inside a landing pad without
corrupting the exception handler, so we have no hope of dealing with
these exceptions anyway. See:
http://llvm.org/docs/ExceptionHandling.html#cleanups
Part of #2861.
