The pristine version of Qt corresponding to this build is available at:
http://viewer-source-downloads.s3.amazonaws.com/install_pkgs/qt-all-opensource-src-4.5.2.tar.bz2

The patches we applied to the above package to get this build are available at:
http://viewer-source-downloads.s3.amazonaws.com/install_pkgs/qtwebkit-linden-patches-20090709.tar.bz2