ICE on unresolved module

[bnoordhuis]

Tested with rustc a831e7c (current HEAD of master).

$ file $HOME/opt/rust/bin/rustc 
/home/bnoordhuis/opt/rust/bin/rustc: ELF 64-bit LSB executable, x86-64, version 1 (SYSV), dynamically linked (uses shared libs), for GNU/Linux 2.6.15, not stripped

$ cat test.rs 
import unresolved::*;

$ RUST_LOG=rustc=0,::rt::backtrace rustc test.rs 
test.rs:1:0: 1:20 error: unresolved modulename: unresolved
test.rs:1 import unresolved::*;
          ^~~~~~~~~~~~~~~~~~~~
rust: upcall fail 'option none', src/libcore/option.rs:34
/home/bnoordhuis/opt/rust/bin/../lib/librustrt.so(_ZN9rust_task4failEv+0x25)[0x7fad4128cb15]
/home/bnoordhuis/opt/rust/bin/../lib/librustrt.so(+0x34c79)[0x7fad412a4c79]
/home/bnoordhuis/opt/rust/bin/../lib/librustrt.so(upcall_fail+0x39)[0x7fad41290e69]
/home/bnoordhuis/opt/rust/bin/../lib/libcore-14bd852465126fe7-0.1.so(_ZN6option3get17_e9fe5bbdaa8f1343E+0xb4)[0x7fad420e0f04]
/home/bnoordhuis/opt/rust/bin/../lib/librustc-4171d83aef249987-0.1.so(_ZN6middle7resolve13follow_import17_39db83e3373c509eE+0x2a1)[0x7fad41884b61]
/home/bnoordhuis/opt/rust/bin/../lib/librustc-4171d83aef249987-0.1.so(_ZN6middle7resolve9map_crate9link_glob17_6c1bca284f9df81eE+0x71)[0x7fad41880ba1]
/home/bnoordhuis/opt/rust/bin/../lib/librustc-4171d83aef249987-0.1.so(+0x304358)[0x7fad41a60358]
/home/bnoordhuis/opt/rust/bin/../lib/librustc-4171d83aef249987-0.1.so(_ZN6syntax5visit9visit_mod17_24466afaa9e1a8b7E+0xad)[0x7fad4191d45d]
/home/bnoordhuis/opt/rust/bin/../lib/librustc-4171d83aef249987-0.1.so(+0x2de742)[0x7fad41a3a742]
/home/bnoordhuis/opt/rust/bin/../lib/librustc-4171d83aef249987-0.1.so(_ZN6middle7resolve9map_crate17_e9f61c552e89e646E+0x852)[0x7fad4187f9a2]
/home/bnoordhuis/opt/rust/bin/../lib/librustc-4171d83aef249987-0.1.so(_ZN6middle7resolve13resolve_crate17_c4c27222d2158d0aE+0x243)[0x7fad4187eab3]
/home/bnoordhuis/opt/rust/bin/../lib/librustc-4171d83aef249987-0.1.so(_ZN6driver6driver4time17_6224b963f79affc8E+0x8c)[0x7fad419cc47c]
/home/bnoordhuis/opt/rust/bin/../lib/librustc-4171d83aef249987-0.1.so(_ZN6driver6driver12compile_upto17_bd712d43acc149bfE+0x957)[0x7fad419cd6b7]
/home/bnoordhuis/opt/rust/bin/../lib/librustc-4171d83aef249987-0.1.so(+0x304358)[0x7fad41a60358]
/home/bnoordhuis/opt/rust/bin/../lib/librustc-4171d83aef249987-0.1.so(_ZN6driver6driver13compile_input17_7c468f6ed9ece9faE+0xc2)[0x7fad419ceca2]
rustc[0x405146]
rustc[0x407948]
rustc[0x40748a]
rustc[0x406f8e]
/home/bnoordhuis/opt/rust/bin/../lib/libcore-14bd852465126fe7-0.1.so(+0x40482)[0x7fad420f0482]
/home/bnoordhuis/opt/rust/bin/../lib/librustrt.so(task_start_wrapper+0x30)[0x7fad4128d3e0]
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/comp/driver/rustc.rs:175
/home/bnoordhuis/opt/rust/bin/../lib/librustrt.so(_ZN9rust_task4failEv+0x25)[0x7fad4128cb15]
/home/bnoordhuis/opt/rust/bin/../lib/librustrt.so(+0x34c79)[0x7fad412a4c79]
/home/bnoordhuis/opt/rust/bin/../lib/librustrt.so(upcall_fail+0x39)[0x7fad41290e69]
rustc[0x4054f2]
rustc[0x40572c]
/home/bnoordhuis/opt/rust/bin/../lib/librustrt.so(task_start_wrapper+0x30)[0x7fad4128d3e0]
rust: domain main @0x1b9cc60 root task failed

[brson]

Appears to be fixed.