27105+3: Fix several tests for 78-81 and add a few new ones

Fixes #27105 (closed), #40001 (closed), #40003 (closed), #40004 (closed), #40005 (closed), #27137 (closed), #28520 (closed), #28665 (closed), #28798 (closed), #28876 (closed), #30333 (closed), #30339 (closed), #30340 (closed), #32537 (closed), #34189 (closed), #40002 (closed).

Supersedes !3 (closed).