Syntactically, Attributes for AccessorDecl are not part of AccessorDecl,
but part of PatternBindingDecl. When the selected range is the brace for
implicit getter, it should be considered as selecting getter decl
regardless of the attributes.
Conversely, we should widen source range for PatternBindingDecl by
looking into declared VarDecls because, in AST, attributes on
PatternBindingDecl are attached to VarDecls.
rdar://problem/41073182