Missing Rascal primitive in the compiler.

[Anastassija]

The following example:

value main(list[value] args) {
    lrel[int,int] r = [];
    return r + <1,2>;    
}

results in the runtime exception:

|rascal://experiments::Compiler::RVM::Run|(217,618,<12,0>,<22,28>): Java("RuntimeException","In function experiments::Compiler::Examples::MyTst/main(list(value());)#0 : No enum constant org.rascalmpl.library.experiments.Compiler.RVM.Interpreter.RascalPrimitive.lrel_add_elm")

Similar exception is thrown in case of rel.