Usage of statically called methods can lead to crash of toolchain

[WojciechMazur]

When adding Scala 2.13.12 to the build I've discovered a strange behaviour - the linking of partestJunitTests for Scala 2.13 was crashing in CodeGen due to no information about java.util.ConcurrentMap.computeIfPresent. This method is now available in java.util.Map, however due to #3475 we cannot override it in ConcurrentMap to allow for accessing it statically.
The failure was originating from scala.collection.convert.EqualsTest when converting ConcurrentMapWrapper to Scala collection. However, when extracting to minimization the issue is no longer reproducable.