Additional changes to Vulkan 1.1 API updates

This commit includes the following:

- Make new/Vulkan 1.1 core commands be optional in codegen.  Before this
  change, the loader crashed when starting with a 1.0 app, and using a 1.0 ICD.
  That's because the loader couldn't find "required" 1.1 entrypoints.  This
  change makes those entrypoints "optional" with a new annotation in the api
  file.

- Changes from internal reviews, including a fix for the algorithm of
  EnumeratePhysicalDeviceGroups.

Test: Run with a 1.0 app with a 1.0 driver and make sure the loader works
Change-Id: I55914b680a1601cb9f3f2cc0257091a0a34ae7f2
diff --git a/vulkan/libvulkan/driver_gen.cpp b/vulkan/libvulkan/driver_gen.cpp
index 5dde133..c6e8a7a 100644
--- a/vulkan/libvulkan/driver_gen.cpp
+++ b/vulkan/libvulkan/driver_gen.cpp
@@ -492,8 +492,7 @@
     INIT_PROC(true, instance, GetPhysicalDeviceProperties);
     INIT_PROC(true, instance, CreateDevice);
     INIT_PROC(true, instance, EnumerateDeviceExtensionProperties);
-    INIT_PROC(true, instance, EnumeratePhysicalDeviceGroups);
-    INIT_PROC_EXT(KHR_swapchain, true, instance, GetPhysicalDevicePresentRectanglesKHR);
+    INIT_PROC(false, instance, EnumeratePhysicalDeviceGroups);
     INIT_PROC_EXT(EXT_debug_report, true, instance, CreateDebugReportCallbackEXT);
     INIT_PROC_EXT(EXT_debug_report, true, instance, DestroyDebugReportCallbackEXT);
     INIT_PROC_EXT(EXT_debug_report, true, instance, DebugReportMessageEXT);
@@ -516,9 +515,7 @@
     INIT_PROC(true, dev, CreateImage);
     INIT_PROC(true, dev, DestroyImage);
     INIT_PROC(true, dev, AllocateCommandBuffers);
-    INIT_PROC(true, dev, GetDeviceQueue2);
-    INIT_PROC_EXT(KHR_swapchain, true, dev, GetDeviceGroupPresentCapabilitiesKHR);
-    INIT_PROC_EXT(KHR_swapchain, true, dev, GetDeviceGroupSurfacePresentModesKHR);
+    INIT_PROC(false, dev, GetDeviceQueue2);
     INIT_PROC_EXT(ANDROID_native_buffer, false, dev, GetSwapchainGrallocUsageANDROID);
     INIT_PROC_EXT(ANDROID_native_buffer, false, dev, GetSwapchainGrallocUsage2ANDROID);
     INIT_PROC_EXT(ANDROID_native_buffer, true, dev, AcquireImageANDROID);