[PATCH v2] string: Improve test-memchr page cross checks

[Yury Khrustalev]

On Mon, May 11, 2026 at 12:58:55PM +0000, Wilco Dijkstra wrote:
> 
> The tests for memchr attempt to check for accidental overreads that cross a page.
> However they weren't done at the end of a page and don't check for the case where
> we match right at the end.  Add buf1_size/buf2_size to make finding end of buffer
> easier.

Nit: Perhaps commit message lines are too wide?

> 
> OK for commit?

LGTM. Reviewed-by: Yury Khrustalev <yury.khrustalev@arm.com>

Thanks,
Yury