A handful of our users have already requested information regarding the Qt 5.4.1 build, that is shipped with IDA 6.9.
Here are the options that were used to build the libraries on:
...\5.4.1\configure.bat "-debug-and-release" "-nomake" "tests" "-qtnamespace" "QT" "-confirm-license" "-accessibility" "-platform" "win32-msvc2015" "-opengl" "desktop" "-force-debug-info" "-prefix" "C:/Qt/5.4.1"
.../5.4.1/configure "-debug-and-release" "-nomake" "tests" "-qtnamespace" "QT" "-confirm-license" "-accessibility" "-platform" "linux-g++-32" "-developer-build" "-fontconfig" "-qt-freetype" "-qt-libpng" "-glib" "-qt-xcb" "-dbus" "-qt-sql-sqlite" "-gtkstyle" "-prefix" "/usr/local/Qt/5.4.1"
.../5.4.1/configure "-debug-and-release" "-nomake" "tests" "-qtnamespace" "QT" "-confirm-license" "-accessibility" "-platform" "macx-g++-32" "-fontconfig" "-qt-freetype" "-qt-libpng" "-qt-sql-sqlite" "-prefix" "/Users/Shared/Qt/5.4.1"
In addition to the specific configure options, the Qt build that ships with IDA includes the following patch. You should therefore apply it to your own Qt 5.4.1 sources before compiling, in order to obtain similar binaries.