[GR-4327] Enabling NB debugger for R library functions.

...fle.r.engine/src/com/oracle/truffle/r/engine/REngine.java

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

...oracle/truffle/r/library/methods/MethodsListDispatch.java

...n/src/com/oracle/truffle/r/nodes/builtin/base/Exists.java

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

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

...in/src/com/oracle/truffle/r/nodes/builtin/base/Parse.java

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

...oracle/truffle/r/nodes/builtin/fastr/FastRSourceInfo.java

.../oracle/truffle/r/nodes/builtin/fastr/FastRTreeStats.java

.../oracle/truffle/r/nodes/builtin/tools/R/tools_overrides.R

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

...ruffle/r/nodes/access/vector/CachedExtractVectorNode.java

...om/oracle/truffle/r/nodes/function/PromiseHelperNode.java

.../src/com/oracle/truffle/r/nodes/function/PromiseNode.java

...oracle/truffle/r/nodes/function/S3FunctionLookupNode.java

.../truffle/r/nodes/objects/CollectGenericArgumentsNode.java

...ser/src/com/oracle/truffle/r/parser/ParserGeneration.java

...acle.truffle.r.parser/src/com/oracle/truffle/r/parser/R.g

....runtime/src/com/oracle/truffle/r/runtime/RSerialize.java