rustpkg strips all crate attributes other than pkgid

[sfackler]

If I build a crate like https://github.com/sfackler/rust-ssl with rustpkg, almost all of the crate attributes are stripped:

> rustpkg install
> rustc --ls .rust/lib/x86_64-unknown-linux-gnu/librust-ssl-8dab4bb9-0.0.so
=Crate Attributes (8dab4bb9f4fff5ebdbe14781c77c825b6ca4ff68c0b80c2e27930d44964863cd)=
#[pkgid = "rust-ssl#0.0"]


=External Dependencies=
1 std-04ff901ef9eb93b7ed8d17b7ddf76fa8eb8b4c7295ad21af7133790d77381330-0.9-pre

But if I build with rustc, they aren't:

> rustc --lib lib.rs
> rustc --ls liblib-9ed81b85-0.0.so
=Crate Attributes (9ed81b850cddab4573c0cde384af6edb8ee6c46b3a139e41b05018f8c3b53079)=
#[feature(struct_variant, macro_rules)]
#[link(name = "rust-ssl",
       vers = "0.1",
       package_id = "github.com/sfackler/rust-ssl")]
#[doc(html_root_url = "http://sfackler.github.io/rust-ssl/doc/rust-ssl/")]
#[pkgid = "lib#0.0"]


=External Dependencies=
1 std-04ff901ef9eb93b7ed8d17b7ddf76fa8eb8b4c7295ad21af7133790d77381330-0.9-pre

[sfackler]

It turns out that this line has been bogus for a while if you were missing a #[link] attribute and now a #[pkgid] attribute: https://github.com/mozilla/rust/blob/master/src/librustpkg/util.rs#L303

[metajack]

Comparing https://github.com/mozilla/rust/blob/1755408d1a58684b6c9bce11aeceb18a1ec2d66e/src/librustpkg/util.rs#L309 with https://github.com/mozilla/rust/blob/master/src/librustpkg/util.rs#L303 it looks like it used to strip everything but link metadata.

The fix for this is to change crate.attrs = ~[...] into a push(...).

[metajack]

This will be fixed by #10948