Refactored GenMatchers.scala to reduce code duplication.
Refactored GenMatchers.scala to reduce code duplication.

scalatest/scalatest,dotty-staging/scalatest,scalatest/scalatest,scalatest/scalatest,cheeseng/scalatest,dotty-staging/scalatest,cheeseng/scalatest,cheeseng/scalatest,dotty-staging/scalatest