Revert "Remove output export call if the output value is undefined"
Revert "Remove output export call if the output value is undefined"

This reverts commit 409ba7456efd70cf59aca7738d791c4efcb53ec2.

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