This changes Dynarmic::A32/A64::Config to store fastmem_pointer in
a std::optional<uintptr_t>, allowing the user to pass a zero base
address for the guest memory, which can be used to effectively
implement a shared address space between the host and the guest.
Converted tests to use oaknut, and added some extra test cases. SSHL's
additional tests are targetd to make sure that the sign of the lowest
byte is used to determine shift direction, not the entire element. USHL
targets this as well as just having more negative (right shift) cases in
general.
Additionally changed the numeric values of the test vectors in the
32-bit element tests to match the pattern of the other tests - this
makes it easier to tell at a glance what elements are out of place if a
test fails.
Yang Liu
Ash
zmt00
Wunkolo
Merry