FOpenGLLinkedProgram * LinkedProgramAndDirtyFlag
We null this when the we dirty PackedGlobalUniformDirty. Thus we can skip all of CommitNonComputeShaderConstants if it matches the current program
FOpenGLLinkedProgram * LinkedProgramAndDirtyFlag
We null this when the we dirty PackedGlobalUniformDirty. Thus we can skip all of CommitNonComputeShaderConstants if it matches the current program