loader: gh888 Add KHR/EXT extensions in vulkan.h

Add the KHR_display_swapchain device extension to the loader
and the core_validation layers.  This fulfills the work required in
JIRA LOAD-7 and gh 90.

Add debug_marker to the extension list.

Change-Id: I1fb70e5d44bc8c1f70fd6d1cfbd106a155081b25
diff --git a/loader/table_ops.h b/loader/table_ops.h
index 5a9abf1..2b4d6d4 100644
--- a/loader/table_ops.h
+++ b/loader/table_ops.h
@@ -276,6 +276,18 @@
     table->GetMemoryWin32HandleNV =
         (PFN_vkGetMemoryWin32HandleNV)gpa(dev, "vkGetMemoryWin32HandleNV");
 #endif // VK_USE_PLATFORM_WIN32_KHR
+    table->CreateSharedSwapchainsKHR =
+        (PFN_vkCreateSharedSwapchainsKHR)gpa(dev, "vkCreateSharedSwapchainsKHR");
+    table->DebugMarkerSetObjectTagEXT =
+        (PFN_vkDebugMarkerSetObjectTagEXT)gpa(dev, "vkDebugMarkerSetObjectTagEXT");
+    table->DebugMarkerSetObjectNameEXT =
+        (PFN_vkDebugMarkerSetObjectNameEXT)gpa(dev, "vkDebugMarkerSetObjectNameEXT");
+    table->CmdDebugMarkerBeginEXT =
+        (PFN_vkCmdDebugMarkerBeginEXT)gpa(dev, "vkCmdDebugMarkerBeginEXT");
+    table->CmdDebugMarkerEndEXT =
+        (PFN_vkCmdDebugMarkerEndEXT)gpa(dev, "vkCmdDebugMarkerEndEXT");
+    table->CmdDebugMarkerInsertEXT =
+        (PFN_vkCmdDebugMarkerInsertEXT)gpa(dev, "vkCmdDebugMarkerInsertEXT");
 }
 
 static inline void *