vulkan: update to header 1.0.42

Updated all necessary files to 1.0.42.  This includes the various
headers as well as the loader, and the parameter validation, object
tracking, and threading layers.  Additionally, bump all layer JSON
files to 1.0.42.

Also, in this change:
  - Enable loader extension automation so that the loader now
    generates all extension entry-points automatically during build
    to reduce likelihood of missing a critical piece on header
    update.
  - Enable layer dispatch table extension automation for the same
    reason.
  - Fixes from Mark Lobodzinski and Tony Barbour to resolve crash
    in loader when working with Intel's Windows driver due to
    GetInstanceProcAddr getting called on inappropriate command
    names.

Change-Id: Ic18d3fac2e145c386c0192031deb5089c91a00d8
diff --git a/layers/parameter_validation_utils.h b/layers/parameter_validation_utils.h
index e3197b6..842268f 100644
--- a/layers/parameter_validation_utils.h
+++ b/layers/parameter_validation_utils.h
@@ -82,6 +82,10 @@
     bool win32_enabled;
     bool display_enabled;
     bool khr_get_phys_dev_properties2_enabled;
+    bool khx_device_group_creation_enabled;
+    bool khx_external_fence_capabilities_enabled;
+    bool khx_external_memory_capabilities_enabled;
+    bool khx_external_semaphore_capabilities_enabled;
     bool ext_acquire_xlib_display_enabled;
     bool ext_direct_mode_display_enabled;
     bool ext_display_surface_counter_enabled;