render_pass:  Add CmdBegin{End}RenderPass()

This is part of rev 47 but was accidentally skipped.
diff --git a/xgl.py b/xgl.py
index 5f09fc1..04e8b2e 100644
--- a/xgl.py
+++ b/xgl.py
@@ -813,6 +813,14 @@
              Param("const XGL_RENDER_PASS_CREATE_INFO*", "pCreateInfo"),
              Param("XGL_RENDER_PASS*", "pRenderPass")]),
 
+        Proto("void", "CmdBeginRenderPass",
+            [Param("XGL_CMD_BUFFER", "cmdBuffer"),
+             Param("XGL_RENDER_PASS", "renderPass")]),
+
+        Proto("void", "CmdEndRenderPass",
+            [Param("XGL_CMD_BUFFER", "cmdBuffer"),
+             Param("XGL_RENDER_PASS", "renderPass")]),
+
         Proto("XGL_RESULT", "DbgSetValidationLevel",
             [Param("XGL_DEVICE", "device"),
              Param("XGL_VALIDATION_LEVEL", "validationLevel")]),