[tree-ssa] Fun with exceptions -- opinions needed

[Jamie Lokier]

Fergus Henderson wrote:
> > This means, that in C++ function calls can clobber the return value, even
> > when they throw,
> 
> In "l = rhs", "l" is not the return value.

When the return value is a struct, and is returned by storing at
a caller-supplied return address, can't the caller pass "&l" as the
address to store at, to elide a copy?

-- Jamie