I implemented FR #65917 (getallheaders() is not supported by the
built-in web server). FR #65917 is actually my own feature request; I
created it because I had tried to use it with the CLI server to test an
application of mine, and it wasn't available. So I went and implemented
it, and since apache_response_headers() complements it and was trivial
to implement as well, I have also implemented that, by copying the
Pull request here: https://github.com/php/php-src/pull/496
The intent is for this to be merged into master (and hopefully 5.6). The
pull request updates NEWS and UPGRADING, as well as adding a test.
Thanks for your time.