rustc -Z debug-info is causing llvm assert failures

[pnkfelix]

% pwd
/Users/pnkfelix/Dev/Mozilla/rust.git
% objdir/x86_64-apple-darwin/stage2/bin/rustc -Z debug-info src/test/run-pass/hello.rs
Assertion failed: (TheCU && "Unable to find compile unit!"), function beginFunction, file /Users/pnkfelix/Dev/Mozilla/rust.git/src/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp, line 1367.
Stack dump:
0. Running pass 'Function Pass Manager' on module 'hello.rc'.

1. Running pass 'X86 Assembly / Object Emitter' on function '@_ZN4main16_113178cfcd612383_00E'
   Illegal instruction: 4

Might be related to #5836

[pnkfelix]

Nominating for milestone #3, "feature complete."

Though if we expect any tools out there to make use of debug-info, then maybe we should be filing this under milestone #2: "backward compatible." (If I could some way to justify getting it into milestone #1, I would...)

[pnkfelix]

Supposedly fixed by commit 4bf074c. I'll close after I check that.

[msullivan]

This was fixed.