[ast-optimizer-branch] simplifying C++

[Jason Merrill]

>>>>> "Joseph" == Joseph S Myers <jsm28@cam.ac.uk> writes:

> C99 doesn't allow decls in the condition (so just does need to enclose the
> loop in a scope - it's because these extra scopes are only applied in C99
> mode that this feature isn't accepted as an extension in gnu89 mode).

Why would that matter?  If decls aren't allowed there in gnu89 mode, what
difference does the extra scope make?

Jason