Code generating override operations would not deal properly with Pointer RNA properties, trying by default to use and check pointers' names properties like it does with items of a collection. However, using name property in pointer RNA property case makes no sense, so specialize the `no_prop_name` flag for each case (pointer or collection). here, since second override would generate local data-blocks with different names than the linked data ones, name matching would fail and breck handling of override diffing in shapekeys. Note that shape keys are the only one concerned by that problem, since other embedded IDs (root node trees and master collections) are fully real ones, so they always get the same names.