ICE on default method with argument with type but no pattern

[huonw]

trait Foo {
    fn bar(&self, int) {} /* should be `x: int` */
}

fn main() {}

error: internal compiler error: unexpected failure
note: the compiler hit an unexpected failure path. this is a bug.
note: we would appreciate a bug report: http://static.rust-lang.org/doc/master/complement-bugreport.html
note: run with `RUST_BACKTRACE=1` for a backtrace
task 'rustc' failed at 'index out of bounds: the len is 0 but the index is 0', /home/rustbuild/src/rust-buildbot/slave/nightly-linux/build/src/librustc/lib.rs:1
stack backtrace:
   1:     0x7f0338b903f0 - rt::backtrace::imp::write::hfeeca528761543758ta::v0.11.pre
   2:     0x7f0338aefed0 - rt::unwind::begin_unwind_inner::had5dce6d998b9190d49::v0.11.pre
   3:     0x7f0338aefe40 - rt::unwind::begin_unwind::h4906696811643339561::v0.11.pre
   4:     0x7f0338b90000 - rt::unwind::begin_unwind_raw::h4129983f13cbbf9bm19::v0.11.pre
   5:     0x7f0338aef170 - rt::unwind::fail_::h237733606292af7c0Y9::v0.11.pre
   6:     0x7f0338b90070 - rt::unwind::fail_bounds_check::closure.40203
   7:     0x7f0338af1100 - rt::unwind::fail_bounds_check::h76f60996a37cba43nZ9::v0.11.pre
   8:     0x7f0339921a30 - middle::lint::Context<'a>.Visitor<(*>::visit_pat::h7788862fd9338443QAC::v0.11.pre
   9:     0x7f0339928610 - visit::walk_fn::h10371742938412987576::v0.11.pre
  10:     0x7f0339928590 - middle::lint::Context<'a>.Visitor<(*>::visit_fn::closure.70839
  11:     0x7f0339928740 - middle::lint::Context<'a>.Visitor<(*>::visit_fn::closure.70841
  12:     0x7f03399074f0 - middle::lint::Context<'a>::with_lint_attrs::h8538146e7841693f1jB::v0.11.pre
  13:     0x7f0339920f00 - middle::lint::Context<'a>.Visitor<(*>::visit_fn::h635e2559e5b35269IDC::v0.11.pre
  14:     0x7f0339918d50 - middle::lint::Context<'a>.Visitor<(*>::visit_item::closure.70825
  15:     0x7f03399074f0 - middle::lint::Context<'a>::with_lint_attrs::h8538146e7841693f1jB::v0.11.pre
  16:     0x7f03399210a0 - visit::Visitor::visit_mod::h9280992652848613719::v0.11.pre
  17:     0x7f033992eca0 - middle::lint::check_crate::closure.70896
  18:     0x7f03399074f0 - middle::lint::Context<'a>::with_lint_attrs::h8538146e7841693f1jB::v0.11.pre
  19:     0x7f033992e430 - middle::lint::check_crate::h8dbd4a4cff79db160JC::v0.11.pre
  20:     0x7f03398d9610 - util::common::time::h5055450459376147389::v0.11.pre
  21:     0x7f0339d18370 - driver::driver::phase_3_run_analysis_passes::h5ad66ddad84915b47Df::v0.11.pre
  22:     0x7f0339d1e280 - driver::driver::compile_input::he9050f82cb7e05a4U3f::v0.11.pre
  23:     0x7f0339d42ef0 - run_compiler::hf931e974d6e8bbdcLAn::v0.11.pre
  24:     0x7f0339d5ad70 - main_args::closure.91499
  25:     0x7f0339d59270 - monitor::closure.91374
  26:     0x7f0339d54b60 - task::TaskBuilder::try::closure.91140
  27:     0x7f033bc1dfb0 - task::spawn_opts::closure.7110
  28:     0x7f0338b8b430 - rt::task::Task::run::closure.40100
  29:     0x7f0338b96350 - rust_try
  30:     0x7f0338b8b270 - rt::task::Task::run::h05318d269ef8d8e5gU7::v0.11.pre
  31:     0x7f033bc1dd80 - task::spawn_opts::closure.7083
  32:     0x7f0338b8ef30 - rt::thread::thread_start::hd5a9dae45ca499e8tz8::v0.11.pre
  33:     0x7f03384c9fa0 - start_thread
  34:     0x7f03387c4a09 - __clone
  35:                0x0 - <unknown>