Add php 5.3 builds.

I ran into an issue with the 5.3 series where the default build (even
using the old official PKGBUILD from arch) failed.  `./configure` was
setting up /lib/cpp as the C preprocessor from the looks of things.
This traced down to an error where makepkg would include _FORTIFY_SOURCE
in CPPFLAGS, configure would attempt to use it at one point, and an
error about _FORTIFY_SOURCE and no optimization flags would cause
configure to report an improper result.  I'm not sure whether a better
change exists, but that'll do for now.