Fix linking lgc with shared libs
Fix linking lgc with shared libs

This allows using lgc with -DBUILD_SHARED_LIBS=ON.

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