OpCapability Shader
          %1 = OpExtInstImport "GLSL.std.450"
               OpMemoryModel Logical GLSL450
               OpEntryPoint Fragment %main "main"
               OpExecutionMode %main OriginUpperLeft
               OpName %main "main"
       %void = OpTypeVoid
          %4 = OpTypeFunction %void
       %main = OpFunction %void None %4
          %5 = OpLabel
               OpReturn
               OpFunctionEnd