Calling tuple struct constructor as a function causes segfault

[lifthrasiir]

This code segfaults (as of a5fae1d 2013-03-08 18:15:40 -0800).

struct A(int);
fn main() {
    let f: extern pure fn(int) -> A = A; f(4);
}

Note that extern pure fn(int) -> A is an exact type reported by the compiler for A. This occurs for arbitrary number of fields. Replacing the body of main to A(4); fixes the segfault.

[catamorphism]

Reproduced with 517bfc9 .

The bug also comes up if you omit the type signature on f. I poked at this a little bit -- it looks like trans stores a **fn(int) into f, but the code generated for the call f(4) treats `fas if it's a*f``. Then I got confused as to which part of the code was correct. I think this isn't critical for 0.7.

[catamorphism]

Nominating for milestone 5 (production-ready).

[graydon]

accepted for production-ready milestone

[emberian]

tuple struct constructor as function is going away with a patch I'm working on.

[emberian]

So that patch never really worked out. But, this is still relevant, and reproduces.