impl priv methods are not private

[cpeterso]

priv fn in an impl does not create a private method. The following code compiles and runs without error, even though shl_unit() is marked priv: https://github.com/mozilla/rust/blob/e447521c1ca2dbead5b485ddc43060b282840817/src/libstd/bigint.rs#L452

extern mod std;
fn main() {
    std::bigint::BigUint::from_uint(2).shl_unit(3);
}

This issue might be related to issue #3452.

[catamorphism]

Bumping to 0.7

[thestinger]

@pcwalton fixed this

foo.rs:3:4: 3:51 error: method `shl_unit` is private
foo.rs:3     std::bigint::BigUint::from_uint(2).shl_unit(3);
             ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
error: aborting due to previous error