A standard memory handler has as a prototype (where uX = u8, u16, u32 or u64):
uX device::read(address_space &space, offs_t offset, uX mem_mask);
void device::write(address_space &space, offs_t offset, uX data, uX mem_mask);
We now allow simplified versions which are:
uX device::read(offs_t offset, uX mem_mask);
void device::write(offs_t offset, uX data, uX mem_mask);
uX device::read(offs_t offset);
void device::write(offs_t offset, uX data);
uX device::read();
void device::write(uX data);
Use them at will. Also consider
(DECLARE_)(READ|WRITE)(8|16|32|64)_MEMBER on the way out, use the
explicit prototypes.
Same for lambdas in the memory map, the parameters are now optional
following the same combinations.
* Make more #include guards follow standard format - using MAME_ as the prefix makes it easy to see which ones come from our code in a preprocessor dump, and having both src/devices/machine/foo.h and src/mame/machine/foo.h causes issues anyway
* Get #include "emu.h" out of headers - it should only be the first thing in a complilation unit or we get differences in behaviour with PCH on/off
* Add out-of-line destructors to some devices - it forces the compiler to instantiate the vtable in a certain location and avoids some non-deterministic compiler behaviours
