Merge pull request #576 from steve-lunarg/uav-registers

Add UAV (image) binding offset and HLSL register class support

diff --cc glslang/MachineIndependent/ShaderLang.cpp
Simple merge

diff --cc glslang/MachineIndependent/localintermediate.h
Simple merge

diff --cc gtests/Hlsl.FromFile.cpp
Simple merge

diff --cc gtests/Spv.FromFile.cpp
Simple merge

diff --cc hlsl/hlslParseHelper.cpp
Simple merge