various fixes and extensions on NFI rffi

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

...le/truffle/r/ffi/impl/nfi/TruffleNFI_UpCallsRFFIImpl.java

...rary/src/com/oracle/truffle/r/library/tools/DirChmod.java

...om/oracle/truffle/r/nodes/builtin/base/FileFunctions.java

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

...ltin/src/com/oracle/truffle/r/nodes/builtin/base/Sum.java

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

.../com/oracle/truffle/r/nodes/builtin/base/foreign/Fft.java

...le.r.runtime/src/com/oracle/truffle/r/runtime/RError.java

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