loader: bug 12992: extension and layer support

Much of layers and loader updated to work with
final extension and layer mechanism.
Not everything is working here.
diff --git a/vk-generate.py b/vk-generate.py
index 1434165..eb3a32a 100755
--- a/vk-generate.py
+++ b/vk-generate.py
@@ -122,7 +122,7 @@
             stmts.append("memset(table, 0, sizeof(*table));")
             stmts.append("table->GetDeviceProcAddr =(PFN_vkGetDeviceProcAddr)  gpa(device,\"vkGetDeviceProcAddr\");")
             for proto in self.protos:
-                if proto.name == "CreateInstance" or proto.name == "GetGlobalExtensionProperties" or proto.name == "GetGlobalExtensionCount" or proto.params[0].ty == "VkInstance" or (proto.params[0].ty == "VkPhysicalDevice" and proto.name != "CreateDevice"):
+                if proto.name == "CreateInstance" or proto.name == "GetGlobalExtensionProperties" or proto.name == "GetGlobalLayerProperties" or proto.params[0].ty == "VkInstance" or (proto.params[0].ty == "VkPhysicalDevice" and proto.name != "CreateDevice"):
                     continue
                 if proto.name != "GetDeviceProcAddr":
                     stmts.append("table->%s = (PFN_vk%s) gpa(baseDevice, \"vk%s\");" %
@@ -251,7 +251,7 @@
                     "GetInstanceProcAddr",
                     "GetDeviceProcAddr",
                     "EnumerateLayers",
-                    "GetGlobalExtensionCount",
+                    "GetGlobalLayerProperties",
                     "GetGlobalExtensionProperties"
                 ],
         }