don't do anything special for stored generated columns
in MyISAM repair code.
add an assert that if there are virtual indexed columns, they
_must_ be beyond the file->s->base.reclength boundary
Problem was that one internal record buffer in MYISAM was not big enough to handle virtual fields.
Fixed by extending buffer.
Fixed test case to 79 characters
* don't issue an error for ER_KEY_BASED_ON_GENERATED_VIRTUAL_COLUMN
* support keyread on vcols
* callback into the server to compute vcol values from mi_check/mi_repair
* DMLs just work. Automatically.
