fix for inherits on function/environment

...src/com/oracle/truffle/r/nodes/builtin/base/Inherits.java

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

.../src/com/oracle/truffle/r/runtime/data/RAttributable.java

...time/src/com/oracle/truffle/r/runtime/data/RFunction.java

...me/src/com/oracle/truffle/r/runtime/env/REnvironment.java

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

...le.r.test/src/com/oracle/truffle/r/test/all/AllTests.java

.../com/oracle/truffle/r/test/simple/TestSimpleBuiltins.java