Thanks to this post I realised that I was missing the xorg-server.pc file. This is installed by the SDK for developing X server driver modules. Doh! Well you live and learn. You can install the SDK from the Fedora xorg-x11-server-sdk package. That done, the driver built beautifully.
If you don's specify the prefix, the drivers get installed to /usr/local/lib/xorg/modules/drivers/ rather than /usr/lib/xorg/modules/drivers/ which is the drivers directory used by Fedora.
And the driver has made absolutely no difference at all :-(
The system says it is still using the "Intel - Experimental modesetting driver for Intel integrated graphics chipsets" video card. More importantly, the display looks just like it did before. Was Fedora already using this driver? I haven't been able to find out. However, the job is only half done. I've built the 2D driver; I now have to build the 3D driver.