Remove SetContextMessageConsumer from markv_codec_test (#1926)
Remove SetContextMessageConsumer from markv_codec_test (#1926)

This CL removes the use of SetContextMessageConsumer from
markv_codec_test and replaces it with a spvtools::Context instead.
antiagainst/SPIRV-Tools,dneto0/SPIRV-Tools,pierremoreau/SPIRV-Tools,antiagainst/SPIRV-Tools,dneto0/SPIRV-Tools,dneto0/SPIRV-Tools,antiagainst/SPIRV-Tools,KhronosGroup/SPIRV-Tools,pierremoreau/SPIRV-Tools,antiagainst/SPIRV-Tools,dneto0/SPIRV-Tools,dneto0/SPIRV-Tools,pierremoreau/SPIRV-Tools,pierremoreau/SPIRV-Tools,antiagainst/SPIRV-Tools,KhronosGroup/SPIRV-Tools,KhronosGroup/SPIRV-Tools,dneto0/SPIRV-Tools,pierremoreau/SPIRV-Tools,pierremoreau/SPIRV-Tools,pierremoreau/SPIRV-Tools,dneto0/SPIRV-Tools,KhronosGroup/SPIRV-Tools,KhronosGroup/SPIRV-Tools,KhronosGroup/SPIRV-Tools,KhronosGroup/SPIRV-Tools,pierremoreau/SPIRV-Tools,KhronosGroup/SPIRV-Tools,dneto0/SPIRV-Tools