program chokes on non-utf8 command line arguments even if it doesn't access them

[jabot2]

Given the test program:

fn main() {
   println!("hello world")
}

When started as following it provides this output and fails with exit status 132

$ ./test a b $'\222'

You've met with a terrible fate, haven't you?

fatal runtime error: Could not unwind stack, error = 5
Illegal instruction

OS: Debian Testing on x86_64

$ rustc --version
rustc 0.13.0-nightly (99d6956c3 2014-12-18 20:32:07 +0000)

[kmcallister]

I narrowed this down to the range 63c4f22 to 8bca470. Bisecting now.

[kmcallister]

git bisect blames this on #19152

[kmcallister]

cc @alexcrichton