[GR-8319] [GR-8050] Revive the GNU R compatible embedding API with NFI backend.

...src/com/oracle/truffle/r/engine/TruffleRLanguageImpl.java

...oracle/truffle/r/engine/shell/EmbeddedConsoleHandler.java

...gine/src/com/oracle/truffle/r/engine/shell/REmbedded.java

...m/oracle/truffle/r/ffi/impl/llvm/TruffleLLVM_Context.java

...om/oracle/truffle/r/ffi/impl/llvm/TruffleLLVM_REmbed.java

...oracle/truffle/r/ffi/impl/managed/Managed_REmbedRFFI.java

...com/oracle/truffle/r/ffi/impl/nfi/TruffleNFI_Context.java

.../com/oracle/truffle/r/ffi/impl/nfi/TruffleNFI_REmbed.java

.../src/com/oracle/truffle/r/ffi/processor/FFIProcessor.java

...m/oracle/truffle/r/launcher/DelegatingConsoleHandler.java

....launcher/src/com/oracle/truffle/r/launcher/RCommand.java

...ncher/src/com/oracle/truffle/r/launcher/RStartParams.java

...her/src/com/oracle/truffle/r/launcher/RscriptCommand.java

com.oracle.truffle.r.native/fficall/Makefile

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

...e.truffle.r.native/fficall/src/truffle_common/Rembedded.c

com.oracle.truffle.r.native/fficall/src/truffle_nfi/Makefile

...acle.truffle.r.native/fficall/src/truffle_nfi/Rembedded.c

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

...tin/src/com/oracle/truffle/r/nodes/builtin/base/Quit.java