[GR-2738] Remove class-hierarchy-related functionality from RAttributable.

...rc/com/oracle/truffle/r/engine/RRuntimeASTAccessImpl.java

...com/oracle/truffle/r/nodes/builtin/base/EnvFunctions.java

.../com/oracle/truffle/r/nodes/builtin/base/GetOldClass.java

...n/src/com/oracle/truffle/r/nodes/builtin/base/IsATTY.java

...cle/truffle/r/nodes/builtin/base/S3DispatchFunctions.java

...n/src/com/oracle/truffle/r/nodes/builtin/base/Unique.java

...acle/truffle/r/nodes/builtin/base/foreign/WriteTable.java

...uffle/r/nodes/builtin/base/printer/AttributesPrinter.java

...ruffle/r/nodes/builtin/base/printer/ValuePrinterNode.java

...e/truffle/r/nodes/builtin/base/printer/ValuePrinters.java

...src/com/oracle/truffle/r/nodes/access/AccessSlotNode.java

...ruffle/r/nodes/access/vector/CachedExtractVectorNode.java

...ruffle/r/nodes/attributes/SpecialAttributesFunctions.java

...s/src/com/oracle/truffle/r/nodes/builtin/CastBuilder.java

...c/com/oracle/truffle/r/nodes/ffi/JavaUpCallsRFFIImpl.java

...m/oracle/truffle/r/nodes/function/ClassHierarchyNode.java

...le/truffle/r/nodes/function/ClassHierarchyScalarNode.java

.../truffle/r/nodes/function/ImplicitClassHierarchyNode.java

....nodes/src/com/oracle/truffle/r/nodes/unary/CastNode.java

...es/src/com/oracle/truffle/r/nodes/unary/IsFactorNode.java