icd: stop generating icd-dispatch-entrypoints.c

Let ICDs define XGL entrypoints directly.  This requires the Intel ICD to
rename intelSomeEntryPoint() to xglSomeEntryPoint().  In addition, the ICD
needs to be linked with -Bsymbolic to make symbol resolving work for
xglGetProcAddr().

v2: use -Bsymbolic-functions
diff --git a/icd/intel/pipeline.c b/icd/intel/pipeline.c
index b2db6ab..0a9997e 100644
--- a/icd/intel/pipeline.c
+++ b/icd/intel/pipeline.c
@@ -899,7 +899,7 @@
     return XGL_SUCCESS;
 }
 
-XGL_RESULT XGLAPI intelCreateGraphicsPipeline(
+ICD_EXPORT XGL_RESULT XGLAPI xglCreateGraphicsPipeline(
     XGL_DEVICE                                  device,
     const XGL_GRAPHICS_PIPELINE_CREATE_INFO*    pCreateInfo,
     XGL_PIPELINE*                               pPipeline)
@@ -910,7 +910,7 @@
             (struct intel_pipeline **) pPipeline);
 }
 
-XGL_RESULT XGLAPI intelCreateComputePipeline(
+ICD_EXPORT XGL_RESULT XGLAPI xglCreateComputePipeline(
     XGL_DEVICE                                  device,
     const XGL_COMPUTE_PIPELINE_CREATE_INFO*     pCreateInfo,
     XGL_PIPELINE*                               pPipeline)
@@ -918,7 +918,7 @@
     return XGL_ERROR_UNAVAILABLE;
 }
 
-XGL_RESULT XGLAPI intelStorePipeline(
+ICD_EXPORT XGL_RESULT XGLAPI xglStorePipeline(
     XGL_PIPELINE                                pipeline,
     XGL_SIZE*                                   pDataSize,
     XGL_VOID*                                   pData)
@@ -926,7 +926,7 @@
     return XGL_ERROR_UNAVAILABLE;
 }
 
-XGL_RESULT XGLAPI intelLoadPipeline(
+ICD_EXPORT XGL_RESULT XGLAPI xglLoadPipeline(
     XGL_DEVICE                                  device,
     XGL_SIZE                                    dataSize,
     const XGL_VOID*                             pData,
@@ -935,7 +935,7 @@
     return XGL_ERROR_UNAVAILABLE;
 }
 
-XGL_RESULT XGLAPI intelCreatePipelineDelta(
+ICD_EXPORT XGL_RESULT XGLAPI xglCreatePipelineDelta(
     XGL_DEVICE                                  device,
     XGL_PIPELINE                                p1,
     XGL_PIPELINE                                p2,