Trade: properly propagate array size from MeshData::attributeData().

The test now passes again.

doc/changelog.dox

@@ -469,6 +469,9 @@ See also:
     propagate errors when delegating to
     @ref Text::AbstractFontConverter::exportFontToSingleData() /
     @ref Text::AbstractFontConverter::exportGlyphCacheToSingleData()
+-   @ref Trade::MeshData::attributeData(UnsignedInt) const was not correctly
+    propagating attribute array size, causing array attributes to appear as
+    non-array
 -   Fixed @ref Platform::GlfwApplication, @ref Platform::Sdl2Application and
     @ref Platform::EmscriptenApplication to correctly print app-specified DPI
     scaling in its verbose output

src/Magnum/Trade/MeshData.cpp

@@ -268,7 +268,7 @@ MeshAttributeData MeshData::attributeData(const UnsignedInt id) const {
     CORRADE_ASSERT(id < _attributes.size(),
         "Trade::MeshData::attributeData(): index" << id << "out of range for" << _attributes.size() << "attributes", MeshAttributeData{});
     const MeshAttributeData& attribute = _attributes[id];
-    return MeshAttributeData{attribute._name, attribute._format, attributeDataViewInternal(attribute)};
+    return MeshAttributeData{attribute._name, attribute._format, attributeDataViewInternal(attribute), attribute._arraySize};
 }
 
 MeshAttribute MeshData::attributeName(const UnsignedInt id) const {