xgl: Remove PIPELINE_DELTA.

bug: 13065
header: 0.60.0

Remove PIPELINE_DELTA.

Add functions for creating and loading pipeline derivatives.

v2: fix warnings (olv)
diff --git a/include/xglLayer.h b/include/xglLayer.h
index 81da19e..cc9f0e9 100644
--- a/include/xglLayer.h
+++ b/include/xglLayer.h
@@ -81,10 +81,11 @@
     xglCreateDepthStencilViewType CreateDepthStencilView;
     xglCreateShaderType CreateShader;
     xglCreateGraphicsPipelineType CreateGraphicsPipeline;
+    xglCreateGraphicsPipelineDerivativeType CreateGraphicsPipelineDerivative;
     xglCreateComputePipelineType CreateComputePipeline;
     xglStorePipelineType StorePipeline;
     xglLoadPipelineType LoadPipeline;
-    xglCreatePipelineDeltaType CreatePipelineDelta;
+    xglLoadPipelineDerivativeType LoadPipelineDerivative;
     xglCreateSamplerType CreateSampler;
     xglCreateDescriptorSetLayoutType CreateDescriptorSetLayout;
     xglBeginDescriptorRegionUpdateType BeginDescriptorRegionUpdate;
@@ -103,7 +104,6 @@
     xglEndCommandBufferType EndCommandBuffer;
     xglResetCommandBufferType ResetCommandBuffer;
     xglCmdBindPipelineType CmdBindPipeline;
-    xglCmdBindPipelineDeltaType CmdBindPipelineDelta;
     xglCmdBindDynamicStateObjectType CmdBindDynamicStateObject;
     xglCmdBindDescriptorSetType CmdBindDescriptorSet;
     xglCmdBindVertexBufferType CmdBindVertexBuffer;