This starts moving a bunch of privacy checks into the privacy
checking phase and out of resolve.

(this will be needed for snapshotting at some point).

and obsolete `-` mode altogether (it *was* parsed as `+` mode).

are currently inferred.  New rules are coming that will require
them to be explicit.  All add some explicit self declarations.

Rename const_view to const_slice
Renamed mut_view to mut_slice

This reverts commit a8f039a0.

correct handling of moves for struct-record update.

Part of #3678.  Fixes #2828, #3904, #4719.

This reverts commit a4250a96.

This is not the cause of the nonexhaustive-match failure.

This reverts commit 8e643525.

LinearMap is quite a bit faster, and is fully owned/sendable without
requiring copies. The older std::map also doesn't use explicit self and
relies on mutable fields.

Make the closure take two arguments instead of a single `path_entry`
struct; remove the `path_entry` type. This eliminates a bad copy.

specifically:

freevars::freevar_entry
ty::{field_ty,AutoAdjustment,AutoRef}
mod::{method_param,method_map_entry}

def-id we have, so that the inliner can distinguish between external and
internal def-ids.  Also add some comments explaining the distinction!

Fixes #4516.

r=graydon