transfer as a write to ensure the memory is writable before starting any
transfer. The fault status information does not reflect this in the 'read'
status bit (i.e. it shows up as a read access), so faults with a RMW access
to non-writable memory was not getting the correct protection. The page would
be read-only and the instruction would fault over and over.
A specific example is when a process forks, and the child process attempts
to execute a RMW access to a data page, which is read-only because it's CoP
Copy-On-Write.
When checking if the page needs to be writablek, also check the locked transfer
and treat any locked transfer as a write.
68060 already handled this correctly, since it has separate read and write
fault bits, and both are set on a RMW access and the trap code was checking
the write status bit.
Fixes PR#36848.
9b0f085da1