many tests are failing after port to new IFunction API

[jurgenvinju]

[ERROR] testBreakNested: <5749,70>(lang.flybytes.tests.RunTests)  Time elapsed: 0.001 s  <<< ERROR!
org.rascalmpl.interpreter.staticErrors.UnsupportedOperation: 
A value of type Mirror (Signature method, list[Mirror] args) is not something you can call like a function, a constructor or a closure.
Advice: |http://tutor.rascal-mpl.org/Errors/Static/UnsupportedOperation/UnsupportedOperation.html|

[jurgenvinju]

all fixed