print len of empty array crashes the compiler

[asterite]

fn main() {
  print!("{}", [].len());
}

$ rustc foo.rs 
foo.rs:2:16: 2:18 error: internal compiler error: borrow-vec associated with bad sty: &ty_err
foo.rs:2   print!("{}", [].len());
                        ^~
note: in expansion of format_args!
<std macros>:2:23: 2:75 note: expansion site
<std macros>:1:1: 3:2 note: in expansion of print!
foo.rs:2:3: 2:26 note: expansion site
note: the compiler hit an unexpected failure path. 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' failed at 'Box<Any>', ../rust/src/libsyntax/ast_util.rs:776

Here's the backtrace:

stack backtrace:
   1:        0x1054f4585 - rt::backtrace::imp::write::h0e26dd8a4a05f6efrGr
   2:        0x1054f7753 - failure::on_fail::h13923e91b81d426ekXr
   3:        0x1057c6dc5 - unwind::begin_unwind_inner::h0fb5ec3809e5b727ufe
   4:        0x10349f912 - unwind::begin_unwind::h10934101626562952781
   5:        0x10349f8a5 - diagnostic::SpanHandler::span_bug::hbc864a0f4923f842juF
   6:        0x102168765 - driver::session::Session::span_bug::h0de2235d8c3f77c3CnB
   7:        0x1024cf7f7 - middle::ty::adjust_ty::borrow_vec::h503dcb9362bdbf17orH
   8:        0x1021745f3 - middle::ty::adjust_ty::hab2c1e32ac4ff50bLkH
   9:        0x102529f77 - middle::typeck::check::regionck::constrain_regions_in_type_of_node::hd6c54389f6332b76XQP
  10:        0x102526114 - middle::typeck::check::regionck::visit_expr::h5784e905d81996ecA1O
  11:        0x10252be27 - visit::walk_expr::h5907329393784617312
  12:        0x1025277bf - middle::typeck::check::regionck::visit_expr::h5784e905d81996ecA1O
  13:        0x10252709b - middle::typeck::check::regionck::visit_expr::h5784e905d81996ecA1O
  14:        0x10252be9a - visit::walk_expr::h5907329393784617312
  15:        0x1025277bf - middle::typeck::check::regionck::visit_expr::h5784e905d81996ecA1O
  16:        0x10252bfb2 - visit::walk_expr::h5907329393784617312
  17:        0x1025277bf - middle::typeck::check::regionck::visit_expr::h5784e905d81996ecA1O
  18:        0x102528fd2 - visit::walk_block::h17786527119977375855
  19:        0x10256d871 - middle::typeck::check::check_bare_fn::h61f052d12e877ddfwBT
  20:        0x102566bcb - middle::typeck::check::check_item::h027777362fa48273EaU
  21:        0x10256d5bd - middle::typeck::check::check_item_types::h2dbd64dceacc2916NAT
  22:        0x101f95f06 - util::common::time::h7630563901268510443
  23:        0x10276aa0c - middle::typeck::check_crate::h39eae4247da0d253fel
  24:        0x102836cb0 - driver::driver::phase_3_run_analysis_passes::h751cf5e050036eb1mPz
  25:        0x102831ca3 - driver::driver::compile_input::hbc61bd8f0f430d03sBz
  26:        0x1028d99d2 - driver::run_compiler::h94bfc1a9a3bd1e6fm9C
  27:        0x1028d80b6 - driver::main_args::closure.137555
  28:        0x1028ea20b - task::TaskBuilder<S>::try_future::closure.138716
  29:        0x1028ea115 - task::TaskBuilder<S>::spawn_internal::closure.138693
  30:        0x1052d984c - task::spawn_opts::closure.8427
  31:        0x10582dd0c - rust_try_inner
  32:        0x10582dcf6 - rust_try
  33:        0x1057c419b - unwind::try::h984411f9abeb5f3dK3d
  34:        0x1057c3f3b - task::Task::run::h9b847fa38b6ea061Bad
  35:        0x1052d96aa - task::spawn_opts::closure.8372
  36:        0x1057c5d56 - thread::thread_start::h9cbcec5684f86e5dnzd
  37:     0x7fff84993899 - _pthread_body
  38:     0x7fff8499372a - _pthread_struct_init

Note that this also triggers the error:

fn main() {
  print!("{}", [1].len());
}

However, if I do this it works:

fn main() {
  print!("{}", [1i].len());
}

[asterite]

Forgot this:

$ rustc --version
rustc 0.12.0-pre (3570095e3 2014-08-19 10:20:54 +0000)

[alexcrichton]

Closing as a dupe of #15730