8078433: javac, some tests are failing after JDK-8078024 because of golden files mismatch
Reviewed-by: darcy

8078024: javac, several incorporation steps are silently failing when an error should be reported
Reviewed-by: mcimadamore

8024154: Fix for 8016177: structural most specific and stuckness breaks 6 langtools tests
Reviewed-by: jjg, jfranck

8016177: structural most specific and stuckness
Reviewed-by: jjg, vromero
Contributed-by: maurizio.cimadamore@oracle.com