Handle another case where creating a constant can fail (#2854)
Handle another case where creating a constant can fail (#2854)

Fixes #2847
KhronosGroup/SPIRV-Tools,antiagainst/SPIRV-Tools,pierremoreau/SPIRV-Tools,pierremoreau/SPIRV-Tools,dneto0/SPIRV-Tools,KhronosGroup/SPIRV-Tools,dneto0/SPIRV-Tools,dneto0/SPIRV-Tools,antiagainst/SPIRV-Tools,dneto0/SPIRV-Tools,antiagainst/SPIRV-Tools,KhronosGroup/SPIRV-Tools,KhronosGroup/SPIRV-Tools,pierremoreau/SPIRV-Tools,KhronosGroup/SPIRV-Tools,pierremoreau/SPIRV-Tools,dneto0/SPIRV-Tools,pierremoreau/SPIRV-Tools,dneto0/SPIRV-Tools,KhronosGroup/SPIRV-Tools,antiagainst/SPIRV-Tools,antiagainst/SPIRV-Tools,pierremoreau/SPIRV-Tools,dneto0/SPIRV-Tools,pierremoreau/SPIRV-Tools,KhronosGroup/SPIRV-Tools,dneto0/SPIRV-Tools,KhronosGroup/SPIRV-Tools,pierremoreau/SPIRV-Tools