[v3] Fix Werror breakage (maintainer-mode)

[Ian Lance Taylor]

"Richard Guenther" <richard.guenther@gmail.com> writes:

> As I said back in the C++ placement new alias bugs the only way to
> honor the C++ memory model is by properly making _all_ stores
> conflict and to disallow hoisting of loads over stores.  For some common
> cases Ian made it work with CHANGE_DYNAMIC_TYPE_EXPR and
> DECL_NO_TBAA, but obviously this isn't enough once a declared type
> is visible to the compiler.

I'll just note for onlookers that while Richard's position is
certainly coherent, there is no general agreement on this point.  See
the blow-by-blow at http://gcc.gnu.org/PR29286 .

Ian