By the way, I just noticed this:
configure: error: Package requirements (libdrm_radeon >= 2.4.31) were not met:

Requested 'libdrm_radeon >= 2.4.31' but version of libdrm_radeon is 2.4.27
My 32bit libdrm is a current -9999 from today. 2.4.27 is the version of the installed 64bit libdrm. Is it possible to fix those configure checks, or would that be outside the scope of your "hack"?