ICE with multiple fails

[14427]

The compiler correctly warns that the second fail is unreachable, then an ICE occurs

fn main() {
    fail ~"One";
    fail ~"Two";
}

[jdm]

#0 rust_task_fail (task=0x10250a1f0, expr=0x100ca7fc0 "Assertion llvm::LLVMGetPointerAddressSpace(val_ty(val)) == gc_box_addrspace failed", file=0x100ca7ed0 "/Users/jdm/src/rust/src/rustc/middle/trans/base.rs", line=270) at /Users/jdm/sr
#1 0x0000000100ffff8b in __morestack () at rust_shape.h:493
#2 0x0000000100fe98af in rust_task::return_c_stack () at /Users/jdm/src/rust/src/rt/rust_task.h:476
#3 0x0000000100fe98af in upcall_fail (expr=<value temporarily unavailable, due to optimizations>, file=0x100ca7ed0 "/Users/jdm/src/rust/src/rustc/middle/trans/base.rs", line=270) at rust_task.h:481
#4 0x0000000100811768 in middle::trans::base::non_gc_box_cast::_68f0d93f43d79376::_05 ()
#5 0x00000001007d8ed0 in middle::trans::tvec::trans_uniq_or_managed_vstore::_fd31b1b42f8448a3::_05 ()
#6 0x00000001007d392c in middle::trans::expr::trans_rvalue_datum_unadjusted::_42733992967a967d::_05 ()
#7 0x00000001007d1602 in middle::trans::expr::trans_to_datum_unadjusted::_42733992967a967d::_05 ()
#8 0x000000010078d0d4 in middle::trans::expr::trans_to_datum::_42733992967a967d::_05 ()
#9 0x0000000100ca2180 in __morestack ()
#10 0x000000010079badb in middle::trans::controlflow::trans_fail_expr::_7b994859dc2c82a::_05 ()

[brson]

Fixed by jdm