Revert bfada89 AMDGPU: Force skip over s_sendmsg and exp instructions
Revert bfada89 AMDGPU: Force skip over s_sendmsg and exp instructions

This is a temporary reversion until we can properly fix a problem where
the done exp of a pixel shader was skipped when all lanes were killed.

Change-Id: If4cbfbe7fe989ca6cd4c54f7bb5cf6ec547e372f

GPUOpen-Drivers/llvm,GPUOpen-Drivers/llvm,GPUOpen-Drivers/llvm,GPUOpen-Drivers/llvm,GPUOpen-Drivers/llvm,GPUOpen-Drivers/llvm,GPUOpen-Drivers/llvm,GPUOpen-Drivers/llvm