SPV: 1st pass implementation of SPV_EXT_shader_viewport_index_layer.
diff --git a/SPIRV/GLSL.ext.KHR.h b/SPIRV/GLSL.ext.KHR.h
index 8a5db3e..2eb10ae 100644
--- a/SPIRV/GLSL.ext.KHR.h
+++ b/SPIRV/GLSL.ext.KHR.h
@@ -43,5 +43,6 @@
 static const char* const E_SPV_KHR_storage_buffer_storage_class = "SPV_KHR_storage_buffer_storage_class";
 static const char* const E_SPV_KHR_post_depth_coverage          = "SPV_KHR_post_depth_coverage";
 static const char* const E_SPV_EXT_shader_stencil_export        = "SPV_EXT_shader_stencil_export";
+static const char* const E_SPV_EXT_shader_viewport_index_layer  = "SPV_EXT_shader_viewport_index_layer";
 
 #endif  // #ifndef GLSLextKHR_H