More pattern matching for empty types changes

Fix is_uninhabited for enum types. It used to assume that an enums variant's
fields were all private.

Fix MIR generation for irrefutable Variant pattern matches. This allows code
like this to work:

    let x: Result<32, !> = Ok(123);
    let Ok(y) = x;

Carry type information on dummy wildcard patterns. Sometimes we need to expand
these patterns into their constructors and we don't want to be expanding a
TyError into a Constructor::Single.

0 files changed, 0 insertions, 0 deletions