GL: Ensure all instanced attributes have a buffer with data

Apple OpenGL drivers sometimes crash when given an instanced draw with
a buffer that has never been given data.

It's not efficient to check if the attribute is both zero-sized and
instanced so just ensure that every time a zero-sized buffer is bound
to an attribute, it gets initialized with some data.

Bug: chromium:1456243
Change-Id: I66b7c7017843153db2df3bc50010cba765d03c5f
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/4642048
Commit-Queue: Geoff Lang <geofflang@chromium.org>
Reviewed-by: Shahbaz Youssefi <syoussefi@chromium.org>

include/platform/autogen/FeaturesGL_autogen.h

@@ -675,6 +675,13 @@ struct FeaturesGL : FeatureSetBase
         &members, "http://crbug.com/1420130"
     };
 
+    FeatureInfo ensureNonEmptyBufferIsBoundForDraw = {
+        "ensureNonEmptyBufferIsBoundForDraw",
+        FeatureCategory::OpenGLFeatures,
+        "Apple OpenGL drivers crash when drawing with a zero-sized buffer bound using a non-zero divisor.",
+        &members, "http://crbug.com/1456243"
+    };
+
 };
 
 inline FeaturesGL::FeaturesGL()  = default;

include/platform/gl_features.json

@@ -731,6 +731,14 @@
                 "Rewrite vec/mat constructors to work around driver bugs"
             ],
             "issue": "http://crbug.com/1420130"
+        },
+        {
+            "name": "ensure_non_empty_buffer_is_bound_for_draw",
+            "category": "Features",
+            "description": [
+                "Apple OpenGL drivers crash when drawing with a zero-sized buffer bound using a non-zero divisor."
+            ],
+            "issue": "http://crbug.com/1456243"
         }
     ]
 }