[cxx-interop] Adjust expectations in a test

Printing an object of a foreign reference type is only supported properly with a new runtime and compiler. When running the tests, we might be testing with an older runtime.

Printing is tested separately in `print-reference.swift`.

Author: egorzhdan

test/Interop/Cxx/foreign-reference/array-of-classes.swift

@@ -61,7 +61,7 @@ func go() {
 
     var loopCount = 0 
     for it in y {
-// CHECK: RefType()
+// CHECK: {{RefType()|(Foreign Reference Type)}}
         print(it)
         loopCount += 1
     }