[RFC] noipa attribute (was Re: How to avoid constant propagation into functions?)

[Florian Weimer]

* Alexander Monakov:

> 2. Can we gently suggest to readers of documentation that this was
> invented for use in the GCC testsuite, and encourage them to seek
> proper alternatives, e.g.:
>
>   This attribute is exposed for the purpose of testing the compiler.
>   In general it should be preferable to properly constrain code
>   generation using the language facilities: for example, using
>   separate compilation or calling through a volatile pointer
>   achieves a similar effect in a portable way

Separate compilation has caveats with LTO, and I don't think the claim
is true for volatile function pointers, as I've already explained.