Issue 1:
rust-encoding builds fine in the previous nightly, but it triggers an ICE in rustc 1.2.0-nightly (0fc0476 2015-05-24) (built 2015-05-24)

This looks similar to #24644, but it started more recently.

$ RUST_BACKTRACE=1 cargo build --verbose
Fresh encoding_index_tests v0.1.4 (file:///home/simon/projects/rust-encoding)
Compiling encoding v0.2.32 (file:///home/simon/projects/rust-encoding)
Running `rustc src/lib.rs --crate-name encoding --crate-type lib -g --out-dir /home/simon/projects/rust-encoding/target/debug --emit=dep-info,link -L dependency=/home/simon/projects/rust-encoding/target/debug -L dependency=/home/simon/projects/rust-encoding/target/debug/deps --extern encoding_index_tradchinese=/home/simon/projects/rust-encoding/target/debug/deps/libencoding_index_tradchinese-9031d0a206975cd9.rlib --extern encoding_index_singlebyte=/home/simon/projects/rust-encoding/target/debug/deps/libencoding_index_singlebyte-80fddc2d153c158e.rlib --extern encoding_index_simpchinese=/home/simon/projects/rust-encoding/target/debug/deps/libencoding_index_simpchinese-06c5fe5964f3071e.rlib --extern encoding_index_korean=/home/simon/projects/rust-encoding/target/debug/deps/libencoding_index_korean-bb2701334d42f010.rlib --extern encoding_index_japanese=/home/simon/projects/rust-encoding/target/debug/deps/libencoding_index_japanese-5e92eb13c020e4d8.rlib`
Fresh libc v0.1.6
Fresh encoding-index-singlebyte v1.20141219.5 (file:///home/simon/projects/rust-encoding)
Fresh encoding-index-simpchinese v1.20141219.5 (file:///home/simon/projects/rust-encoding)
Fresh encoding-index-korean v1.20141219.5 (file:///home/simon/projects/rust-encoding)
Fresh encoding-index-japanese v1.20141219.5 (file:///home/simon/projects/rust-encoding)
Fresh encoding-index-tradchinese v1.20141219.5 (file:///home/simon/projects/rust-encoding)
Fresh log v0.3.1
Fresh getopts v0.2.10
error: internal compiler error: unexpected panic
note: the compiler unexpectedly panicked. this is a bug.
note: we would appreciate a bug report: https://github.com/rust-lang/rust/blob/master/CONTRIBUTING.md#bug-reports
note: run with `RUST_BACKTRACE=1` for a backtrace
thread 'rustc' panicked at 'assertion failed: prev_const.is_none() || prev_const == Some(llconst)', /home/rustbuild/src/rust-buildbot/slave/nightly-dist-rustc-linux/build/src/librustc_trans/trans/consts.rs:291

stack backtrace:
1: 0x7f38ec7687e9 - sys::backtrace::write::he19dad14fe2b97b1w6r
2: 0x7f38ec7707a9 - panicking::on_panic::h330377024750b34dHMw
3: 0x7f38ec731482 - rt::unwind::begin_unwind_inner::h7703fc192c11eec8Rrw
4: 0x7f38eb4d782e - rt::unwind::begin_unwind::h7587717121668466740
5: 0x7f38eb549830 - trans::consts::const_expr::h6a02570a980db0cdhNs
6: 0x7f38eb5a1aea - trans::consts::get_const_expr_as_global::h8d682e42aa0c00a1pKs
7: 0x7f38eb51bf3f - trans::expr::trans::h063786072022aec6izA
8: 0x7f38eb5b80ce - trans::expr::trans_into::h0995470e7b548e00ZsA
9: 0x7f38eb53d9d2 - trans::expr::trans_adt::h7fc068c005b70b7fv8B
10: 0x7f38eb5e38b2 - trans::expr::trans_rvalue_dps_unadjusted::he15a7fa64af631b8MCB
11: 0x7f38eb5b831c - trans::expr::trans_into::h0995470e7b548e00ZsA
12: 0x7f38eb53ba66 - trans::controlflow::trans_block::h6757ec40476ddde4slv
13: 0x7f38eb5e3bbd - trans::expr::trans_rvalue_dps_unadjusted::he15a7fa64af631b8MCB
14: 0x7f38eb5b831c - trans::expr::trans_into::h0995470e7b548e00ZsA
15: 0x7f38eb53ba66 - trans::controlflow::trans_block::h6757ec40476ddde4slv
16: 0x7f38eb53a381 - trans::base::trans_closure::hdcc3c01c9bca642e7Uh
17: 0x7f38eb53c05a - trans::base::trans_fn::hf52d8c0c091fdef5P5h
18: 0x7f38eb53ee27 - trans::base::trans_item::he4dc60caaf1684eajui
19: 0x7f38eb53f738 - trans::base::trans_item::he4dc60caaf1684eajui
20: 0x7f38eb54ccfc - trans::base::trans_crate::hb11747a7cf1143a4sjj
21: 0x7f38eccc14a4 - driver::phase_4_translate_to_llvm::h29a0d7314fcd3b41nOa
22: 0x7f38ecc9d226 - driver::compile_input::h16cddbb7992cbbbaQba
23: 0x7f38ecd52f21 - run_compiler::h74084e004617dcdcb6b
24: 0x7f38ecd50772 - boxed::F.FnBox<A>::call_box::h10784738899208612549
25: 0x7f38ecd4ff49 - rt::unwind::try::try_fn::h5235027869346842134
26: 0x7f38ec7e9498 - rust_try_inner
27: 0x7f38ec7e9485 - rust_try
28: 0x7f38ec75c247 - rt::unwind::try::inner_try::hb6f04bd1baacc20eKnw
29: 0x7f38ecd5017a - boxed::F.FnBox<A>::call_box::h17245911238432039576
30: 0x7f38ec76f471 - sys::thread::Thread::new::thread_start::h285dd80d49b81cf50xv
31: 0x7f38e6798373 - start_thread
32: 0x7f38ec3c127c - clone
33: 0x0 - <unknown>

Could not compile `encoding`.

Caused by:
Process didn't exit successfully: `rustc src/lib.rs --crate-name encoding --crate-type lib -g --out-dir /home/simon/projects/rust-encoding/target/debug --emit=dep-info,link -L dependency=/home/simon/projects/rust-encoding/target/debug -L dependency=/home/simon/projects/rust-encoding/target/debug/deps --extern encoding_index_tradchinese=/home/simon/projects/rust-encoding/target/debug/deps/libencoding_index_tradchinese-9031d0a206975cd9.rlib --extern encoding_index_singlebyte=/home/simon/projects/rust-encoding/target/debug/deps/libencoding_index_singlebyte-80fddc2d153c158e.rlib --extern encoding_index_simpchinese=/home/simon/projects/rust-encoding/target/debug/deps/libencoding_index_simpchinese-06c5fe5964f3071e.rlib --extern encoding_index_korean=/home/simon/projects/rust-encoding/target/debug/deps/libencoding_index_korean-bb2701334d42f010.rlib --extern encoding_index_japanese=/home/simon/projects/rust-encoding/target/debug/deps/libencoding_index_japanese-5e92eb13c020e4d8.rlib` (exit code: 101)

Issue 2:
Code

trait Trait {}

struct Bar;
impl Trait for Bar {}

fn main() {
let x: &[&Trait] = &[{ &Bar }];
}

Output

main.rs:7:9: 7:10 warning: unused variable: `x`, #[warn(unused_variables)] on by default
main.rs:7 let x: &[&Trait] = &[{ &Bar }];
^
error: internal compiler error: unexpected panic
note: the compiler unexpectedly panicked. this is a bug.
note: we would appreciate a bug report: https://github.com/rust-lang/rust/blob/master/CONTRIBUTING.md#bug-reports
note: run with `RUST_BACKTRACE=1` for a backtrace
thread 'rustc' panicked at 'assertion failed: prev_const.is_none() || prev_const == Some(llconst)', /Users/rustbuild/src/rust-buildbot/slave/nightly-dist-rustc-mac/build/src/librustc_trans/trans/consts.rs:321

stack backtrace:
1: 0x1054eb5cf - sys::backtrace::write::h9137c695ab290a14WRs
2: 0x1054f3b82 - panicking::on_panic::h0ae3cf09aff03bc05Pw
3: 0x1054a9d15 - rt::unwind::begin_unwind_inner::h36b4206cb80fb108Oxw
4: 0x102149fcf - rt::unwind::begin_unwind::h6767503471583286242
5: 0x1021c082c - trans::consts::const_expr::h1bbfa5560b941f32nvs
6: 0x102224922 - vec::Vec<T>.FromIterator<T>::from_iter::h7466739370638199104
7: 0x10221baea - trans::consts::const_expr_unadjusted::hd675727493ff08eezLs
8: 0x1021bfff7 - trans::consts::const_expr::h1bbfa5560b941f32nvs
9: 0x10221dc67 - trans::consts::const_expr_unadjusted::hd675727493ff08eezLs
10: 0x1021bfff7 - trans::consts::const_expr::h1bbfa5560b941f32nvs
11: 0x10221a9f9 - trans::consts::get_const_expr_as_global::h2f40511a988c5876yss
12: 0x10218f6ca - trans::expr::trans::h959669806b495bbffdA
13: 0x1022314e0 - trans::expr::trans_into::h43738e587d521f35W6z
14: 0x1022b4e21 - trans::_match::mk_binding_alloca::h2459388509959927399
15: 0x1021a09b9 - trans::base::init_local::h8acf9c70632535fdNVg
16: 0x1021b1453 - trans::controlflow::trans_block::hb872ebbfd195606cZ2u
17: 0x1021b0105 - trans::base::trans_closure::hbf7fcb6cfae5e775KCh
18: 0x1021b1d9e - trans::base::trans_fn::hb08e54207cb8d8e6sNh
19: 0x1021b5308 - trans::base::trans_item::h15647b08683789dbEbi
20: 0x1021c40f0 - trans::base::trans_crate::hdfbb43ad3281f84dE0i
21: 0x101c4fdde - driver::phase_4_translate_to_llvm::he9458af7df85ffb8lOa
22: 0x101c28344 - driver::compile_input::h3c162f55ed6be3a5Qba
23: 0x101cef853 - run_compiler::hae39edbb343296d3D4b
24: 0x101ced37a - boxed::F.FnBox<A>::call_box::h1927805197202631788
25: 0x101cec817 - rt::unwind::try::try_fn::h7355792964568869981
26: 0x10557d998 - rust_try_inner
27: 0x10557d985 - rust_try
28: 0x101cecaf0 - boxed::F.FnBox<A>::call_box::h2359980489235781969
29: 0x1054f26cd - sys::thread::create::thread_start::hfa406746e663ba1bNUv
30: 0x7fff81be3267 - _pthread_body
31: 0x7fff81be31e4 - _pthread_start

Rust Version

rustc 1.0.0-nightly (1284be404 2015-04-18) (built 2015-04-17)
binary: rustc
commit-hash: 1284be4044420bc4c41767284ae26be61a38d331
commit-date: 2015-04-18
build-date: 2015-04-17
host: x86_64-apple-darwin
release: 1.0.0-nightly