Issue 1:
#![feature(associated_types)]

impl Foo for int {
type A = uint;
}

pub trait Foo {
type A;
}

pub fn main() {}

task 'rustc' panicked at 'No def'n found for DefId { krate: 0, node: 13 } in tcx.impl_or_trait_items', /home/ncameron/rust/src/librustc/middle/ty.rs:4310

stack backtrace:
1: 0x7f1940943440 - rt::backtrace::imp::write::h0f67e562de667d35Gay
2: 0x7f19409478b0 - failure::on_fail::h58a0ff7a5099a6000Cy
3: 0x7f19405fec80 - unwind::begin_unwind_inner::ha57e93b5d4f1f80d1Qc
4: 0x7f19405fe7e0 - unwind::begin_unwind_fmt::ha9fc4b78efd146fccOc
5: 0x7f193f4ead30 - middle::ty::impl_or_trait_item::h55c274f1e1ee9b78Xl8
6: 0x7f193f95cc40 - middle::typeck::collect::ImplCtxt<'a, 'tcx>.AstConv<'tcx>::associated_type_binding::hcc097ca1cd60b433DCK
7: 0x7f193f994750 - middle::typeck::astconv::create_substs_for_ast_path::h12687352172379627279
8: 0x7f193f87e830 - middle::typeck::collect::convert::h51f7fcfe7a681561cXK
9: 0x7f193f878890 - middle::typeck::collect::collect_item_types::hf182a64ac9f0ea5eORJ
10: 0x7f193f751d10 - util::common::time::h13554638601947919603
11: 0x7f193f751310 - middle::typeck::check_crate::h9b48aa6c28528690bQP
12: 0x7f1940f43120 - driver::driver::phase_3_run_analysis_passes::h938db519a111a7574nS
13: 0x7f1940f3c410 - driver::driver::compile_input::h282769b6ecf9b18b44R
14: 0x7f1940fb9260 - driver::run::closure.61472
15: 0x7f1940fc6290 - task::TaskBuilder::try_future::closure.62104
16: 0x7f194093a910 - task::TaskBuilder::spawn_internal::closure.31177
17: 0x7f1940600b90 - task::Task::spawn::closure.5779
18: 0x7f194065b090 - rust_try_inner
19: 0x7f194065b080 - rust_try
20: 0x7f19405fe540 - unwind::try::heee2f446c60ea967mFc
21: 0x7f1940600a40 - task::Task::run::h7f1d4c2e55b46abdeOb
22: 0x7f1940600810 - task::Task::spawn::closure.5755
23: 0x7f1940604350 - thread::thread_start::hc7adf40c9d3bfc57h6b
24: 0x7f193b83a0c0 - start_thread
25: 0x7f19402bef89 - __clone
26: 0x0 - <unknown>

Issue 2:
Not sure how to properly describe the bug, but this causes an ICE:

#![feature(associated_types)]

struct SimulationInfo;

impl SimulationInfo {
fn add_state<T: HasState>(&mut self, op: || -> <T as HasState>::State)
-> Option<&mut <T as HasState>::State> {
None
}
}

trait HasState {
type State;
}

Whereas this compiles:

#![feature(associated_types)]

struct SimulationInfo;

trait HasState {
type State;
}

impl SimulationInfo {
fn add_state<T: HasState>(&mut self, op: || -> <T as HasState>::State)
-> Option<&mut <T as HasState>::State> {
None
}
}

Failure:

error: internal compiler error: unexpected panic
note: the compiler unexpectedly panicked. this is a bug.
note: we would appreciate a bug report: http://doc.rust-lang.org/complement-bugreport.html
note: run with `RUST_BACKTRACE=1` for a backtrace
task 'rustc' panicked at 'No def'n found for DefId { krate: 0, node: 33 } in tcx.impl_or_trait_items', /Users/rustbuild/src/rust-buildbot/slave/nightly-mac/build/src/librustc/middle/ty.rs:4066

stack backtrace:
1: 0x10d45a619 - rt::backtrace::imp::write::h03fee16d4a0b6b41moq
2: 0x10d45d85c - failure::on_fail::h3e0f6b3c6c4bbcc3VEq
3: 0x10d6bcf05 - unwind::begin_unwind_inner::h6c7f4532e72658d7SJd
4: 0x10d6bcb9f - unwind::begin_unwind_fmt::h9863b25c438d6314kHd
5: 0x10a408d50 - middle::ty::impl_or_trait_item::h8676078de6338b03J2J
6: 0x10a7fe51e - middle::typeck::collect::convert_methods::ty_of_method::h1b65fc29f839dd39kEi
7: 0x10a7a4b84 - middle::typeck::collect::convert::hf5d19782a9342fbfL7i
8: 0x10a79c993 - middle::typeck::collect::collect_item_types::h2af040048993f98298h
9: 0x10a1bb556 - util::common::time::h11920059333862041717
10: 0x10a965478 - middle::typeck::check_crate::h50fcc5c8b39993f4LVn
11: 0x10a9cdbcf - driver::driver::phase_3_run_analysis_passes::h1425a4ca465c7b097DA
12: 0x10a9c82b8 - driver::driver::compile_input::h60bc42ef7fabbfd4SkA
13: 0x10aa45ca8 - driver::run_compiler::h4031243f49082a9fw7D
14: 0x10aa43ece - driver::run::closure.145349
15: 0x10a1d381b - task::TaskBuilder<S>::try_future::closure.103709
16: 0x10a1d3713 - task::TaskBuilder<S>::spawn_internal::closure.103680
17: 0x10a15398d - task::NativeSpawner.Spawner::spawn::closure.8526
18: 0x10d72320c - rust_try_inner
19: 0x10d7231f6 - rust_try
20: 0x10d6ba677 - unwind::try::hab84862d0081b274cyd
21: 0x10d6ba50c - task::Task::run::h39093ecd59554b49ZJc
22: 0x10a1537b3 - task::NativeSpawner.Spawner::spawn::closure.8463
23: 0x10d6bbd37 - thread::thread_start::h589be8c0a398d299e5c
24: 0x7fff9260c2fc - _pthread_body
25: 0x7fff9260c279 - _pthread_body