Update GL headers

thirdparty/include/GLES3/gl31.h

@@ -6,28 +6,9 @@ extern "C" {
 #endif
 
 /*
-** Copyright (c) 2013-2018 The Khronos Group Inc.
+** Copyright 2013-2020 The Khronos Group Inc.
+** SPDX-License-Identifier: MIT
 **
-** Permission is hereby granted, free of charge, to any person obtaining a
-** copy of this software and/or associated documentation files (the
-** "Materials"), to deal in the Materials without restriction, including
-** without limitation the rights to use, copy, modify, merge, publish,
-** distribute, sublicense, and/or sell copies of the Materials, and to
-** permit persons to whom the Materials are furnished to do so, subject to
-** the following conditions:
-**
-** The above copyright notice and this permission notice shall be included
-** in all copies or substantial portions of the Materials.
-**
-** THE MATERIALS ARE PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
-** EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
-** MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
-** IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
-** CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
-** TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
-** MATERIALS OR THE USE OR OTHER DEALINGS IN THE MATERIALS.
-*/
-/*
 ** This header is generated from the Khronos OpenGL / OpenGL ES XML
 ** API Registry. The current version of the Registry, generator scripts
 ** used to make the header, and the header can be found at