Print more warnings to the .err log if ALTER TABLE ... IMPORT TABLESPACE fails for some reason
os0file.c:
  Do not call exit(1) if os_file_delete() fails; remove unused parameter from
handle_error_no_exit()

fil0fil.c:
  Allow DROP TABLE even if the .ibd file for the table does not exist


innobase/fil/fil0fil.c:
  Allow DROP TABLE even if the .ibd file for the table does not exist
innobase/os/os0file.c:
  Dono not call exit(1) if os_file_delete() fails; remove unused parameter from handle_error_no_exit()
innobase/row/row0mysql.c:
  Print more warnings to the .err log if ALTER TABLE ... IMPORT TABLESPACE fails for some reason