Implemented functions 'R_has_slot' and 'CLOENV'.

...oracle/truffle/r/ffi/impl/common/JavaUpCallsRFFIImpl.java

...c/com/oracle/truffle/r/ffi/impl/nodes/DuplicateNodes.java

...pl/src/com/oracle/truffle/r/ffi/impl/nodes/MiscNodes.java

...com/oracle/truffle/r/ffi/impl/upcalls/StdUpCallsRFFI.java

...om/oracle/truffle/r/library/methods/SubstituteDirect.java

...oracle.truffle.r.native/fficall/src/common/rffi_upcalls.h

...e.truffle.r.native/fficall/src/common/rffi_upcallsindex.h

...ve/fficall/src/truffle_common/Rinternals_truffle_common.h

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

...src/com/oracle/truffle/r/nodes/builtin/base/List2Env.java

...m/oracle/truffle/r/nodes/builtin/base/RecordGraphics.java

...c/com/oracle/truffle/r/nodes/builtin/base/Substitute.java

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

...com/oracle/truffle/r/nodes/access/BaseAccessSlotNode.java

...es/src/com/oracle/truffle/r/nodes/access/HasSlotNode.java

.../com/oracle/truffle/r/nodes/builtin/EnvironmentNodes.java

...src/com/oracle/truffle/r/nodes/builtin/RList2EnvNode.java