rustc: List metadata fails with class

[lht]

#[crate_type = "lib"];

class foo {
    let mut x: int;
    new(xx: int) { self.x = xx; }
}

$ RUST_LOG=rustc=0,::rt::backtrace rustc --ls libfoo-459068b0a4d848ae-0.0.so
=Crate Attributes (459068b0a4d848ae)=
#[crate_type = "lib"]
#[link(name = "foo", vers = "0.0")]


=External Dependencies=
1 core-d27e4777a53c3e50-0.2

=Items=
foo (class)
foo (fn)
rust: upcall fail 'option none', ../src/rustc/rustc.rc:1
/opt/apps/rust/bin/../lib/librustrt.so(_ZN9rust_task4failEv+0x28)[0x7f54310f5338]
/opt/apps/rust/bin/../lib/librustrt.so(+0x30039)[0x7f5431109039]
/opt/apps/rust/bin/../lib/librustrt.so(upcall_fail+0x161)[0x7f54310f8241]
/opt/apps/rust/bin/../lib/librustc-688fa7810161fd45-0.2.so(+0x659d60)[0x7f5431792d60]
/opt/apps/rust/bin/../lib/librustc-688fa7810161fd45-0.2.so(+0x659c6f)[0x7f5431792c6f]
/opt/apps/rust/bin/../lib/librustc-688fa7810161fd45-0.2.so(+0x662de8)[0x7f543179bde8]
/opt/apps/rust/bin/../lib/librustc-688fa7810161fd45-0.2.so(+0x667848)[0x7f54317a0848]
/opt/apps/rust/bin/../lib/librustc-688fa7810161fd45-0.2.so(+0x668148)[0x7f54317a1148]
/opt/apps/rust/bin/../lib/libstd-d399da1ab6f5bec0-0.2.so(_ZN4ebml11tagged_docs17_822384a6257887eb202E+0x101)[0x7f54325554c1]
/opt/apps/rust/bin/../lib/librustc-688fa7810161fd45-0.2.so(+0x667e3e)[0x7f54317a0e3e]
/opt/apps/rust/bin/../lib/libstd-d399da1ab6f5bec0-0.2.so(_ZN4ebml11tagged_docs17_822384a6257887eb202E+0x101)[0x7f54325554c1]
/opt/apps/rust/bin/../lib/librustc-688fa7810161fd45-0.2.so(+0x66742e)[0x7f54317a042e]
/opt/apps/rust/bin/../lib/librustc-688fa7810161fd45-0.2.so(+0x6671ee)[0x7f54317a01ee]
/opt/apps/rust/bin/../lib/librustc-688fa7810161fd45-0.2.so(+0x66ec57)[0x7f54317a7c57]
/opt/apps/rust/bin/../lib/librustc-688fa7810161fd45-0.2.so(+0x6c6b18)[0x7f54317ffb18]
/opt/apps/rust/bin/../lib/librustc-688fa7810161fd45-0.2.so(_ZN8metadata7creader18list_file_metadata17_0e2fb2f77bacb5af202E+0x92)[0x7f54317b0332]
/opt/apps/rust/bin/../lib/librustc-688fa7810161fd45-0.2.so(_ZN6driver6driver13list_metadata17_0e2fb2f77bacb5af202E+0x52)[0x7f54317e5d32]
rustc[0x404de9]
rustc[0x40e5cc]
rustc[0x40e10b]
rustc[0x40d4bc]
rustc[0x40c642]
/opt/apps/rust/bin/../lib/libcore-d27e4777a53c3e50-0.2.so(+0x8ee79)[0x7f5432309e79]
/opt/apps/rust/bin/../lib/librustrt.so(_Z18task_start_wrapperP10spawn_args+0x2b)[0x7f54310f5c4b]
error: internal compiler error unexpected failure
note: The compiler hit an unexpected failure path. This is a bug. Try running with RUST_LOG=rustc=0,::rt::backtrace to get further details and report the results to github.com/mozilla/rust/issues
rust: upcall fail 'explicit failure', ../src/rustc/driver/rustc.rs:187
/opt/apps/rust/bin/../lib/librustrt.so(_ZN9rust_task4failEv+0x28)[0x7f54310f5338]
/opt/apps/rust/bin/../lib/librustrt.so(+0x30039)[0x7f5431109039]
/opt/apps/rust/bin/../lib/librustrt.so(upcall_fail+0x161)[0x7f54310f8241]
rustc[0x40af1e]
rustc[0x40e5cc]
rustc[0x40df79]
rustc[0x40e042]
/opt/apps/rust/bin/../lib/librustrt.so(_Z18task_start_wrapperP10spawn_args+0x2b)[0x7f54310f5c4b]
rust: domain main @0xcc0eb0 root task failed

[catamorphism]

Fixed in 8ed970 and f1acc6, but there's no test case since I'm not sure how to test the --ls option.