Autogenerate ANGLE extension entry points

Modify autogeneration script to pull data from gl_ext.xml and generate
entry_points_gles_2_0_ext_autogen.cpp/h as a replacement for
entry_points_gles_2_0_ext.cpp/h

Bug:angleproject:2263
Bug:angleproject:1309
Change-Id: Ie21079f8ec5f85c657b891f6d6d59306a4c3b5fe
Reviewed-on: https://chromium-review.googlesource.com/1005409
Commit-Queue: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Geoff Lang <geofflang@chromium.org>
Reviewed-by: Jamie Madill <jmadill@chromium.org>
diff --git a/src/libANGLE/validationES2.cpp b/src/libANGLE/validationES2.cpp
index bb164ef..cdb79c9 100644
--- a/src/libANGLE/validationES2.cpp
+++ b/src/libANGLE/validationES2.cpp
@@ -2623,17 +2623,17 @@
                                            pixels);
 }
 
-bool ValidateTexImage2DRobust(Context *context,
-                              TextureTarget target,
-                              GLint level,
-                              GLint internalformat,
-                              GLsizei width,
-                              GLsizei height,
-                              GLint border,
-                              GLenum format,
-                              GLenum type,
-                              GLsizei bufSize,
-                              const void *pixels)
+bool ValidateTexImage2DRobustANGLE(Context *context,
+                                   TextureTarget target,
+                                   GLint level,
+                                   GLint internalformat,
+                                   GLsizei width,
+                                   GLsizei height,
+                                   GLint border,
+                                   GLenum format,
+                                   GLenum type,
+                                   GLsizei bufSize,
+                                   const void *pixels)
 {
     if (!ValidateRobustEntryPoint(context, bufSize))
     {