Improve SAM type closure parameter type inferencing

[eric-milles]

Consider the following:

@FunctionalInterface
interface Sam {
  int meth(int a, Long b, java.util.regex.Pattern c);
}

// both cases should inference 'a' as int, 'b' as Long and 'c' as Pattern
Sam type = { a, b, c -> ... }
def type = { a, b, c -> ... } as Sam

[eric-milles]

This same type inferencing already exists for:

def m(Sam t) { ... }
m { a, b, c -> ... }