Options of fixing biggest alignment in PR target/38736

[Ian Lance Taylor]

"H.J. Lu" <hjl.tools@gmail.com> writes:

> We can solve it with
>
> 1. A target should define MALLOC_ABI_ALIGNMENT properly.
> 2. g++ should issue an error when the default new operator
> is used on a type whose alignment is greater than
> MALLOC_ABI_ALIGNMENT.
> 3. It is user's responsibility to provide a new operator to return
> a properly aligned memory.
> 4. g++ can assume memory return by the user-provided new
> operator is properly aligned.

Sounds good as far as it goes.  How do we get there from here?  What
should the behaviour of __attribute__ ((aligned)) be?  Should we add
any new __attribute ((aligned (XXX))) options?

Ian