XBMC's configure script checks for this function in installed
libavcodec.so to determine VDPAU support.
Fixes ticket #762 reported by Christian Marillat
(cherry picked from commit 9994643fdd6c06b4f986be8879953a139fbd1a40)
This significantly reduces the size of the symbol table in the generated ELF
shared object (as well as the other linked tables).
Signed-off-by: Mans Rullgard <mans@mansr.com>