Integrated handling of active bindings into frame access.

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

.../oracle/truffle/r/nodes/access/BaseWriteVariableNode.java

...uffle/r/nodes/access/variables/LocalReadVariableNode.java

...le/truffle/r/nodes/access/variables/ReadVariableNode.java

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

...es/src/com/oracle/truffle/r/nodes/function/RCallNode.java

...rc/com/oracle/truffle/r/runtime/PrimitiveMethodsInfo.java

...com/oracle/truffle/r/runtime/env/frame/ActiveBinding.java

...e/truffle/r/runtime/env/frame/FrameSlotChangeMonitor.java

...e/truffle/r/runtime/env/frame/REnvTruffleFrameAccess.java

...est/src/com/oracle/truffle/r/test/ExpectedTestOutput.test

...uffle.r.test/src/com/oracle/truffle/r/test/S4/TestR5.java

...uffle.r.test/src/com/oracle/truffle/r/test/S4/TestS4.java