Take spvgen.h with ability to load spvgen.so from specified directory
Take spvgen.h with ability to load spvgen.so from specified directory

Change-Id: I9b05670c1fed7cd351f63cf7f87947d96e9e25e5

googlestadia/llpc,GPUOpen-Drivers/llpc,GPUOpen-Drivers/llpc,googlestadia/llpc,GPUOpen-Drivers/llpc,GPUOpen-Drivers/llpc,googlestadia/llpc,googlestadia/llpc,googlestadia/llpc,GPUOpen-Drivers/llpc