These environment variables would linger after the `php` port was done
building. This would pose issues in the future if other ports depend on
this package, since these vars then leak into the build scripts.
We may need entries with spaces in makeopts, installopts, and
configopts, and at that point we should also convert depends and
auth_opts to avoid confusion.
The PCRE JIT creates memory that needs to be readable, writable and
executable at the same time. Serenity does not like this, so disable
it. This JIT is of limited use for the current applications of PHP
within Serenity anyway :-)