[builds/unix] Do not use autoconf SIZEOF.

* builds/unix/ftconfig.h.in [FT_USE_AUTOCONF_SIZEOF_TYPES]: Removed.
* builds/unix/configure.raw: Remove AC_CHECK_SIZEOF and update.

After this commit, autoconf builds will fully rely on <limits.h>
rather than falling back on it if AC_CHECK_SIZEOF failed for some
reason.  There is a risk that misconfigured cross-compilation might
have wrong headers.  Note that Meson and CMake builds always relied on
<limits.h> for sizes and availability of integer types.
2 files changed