This is around 8% perf improvement alone.
This also fixes many flag calculation/usage bugs (in corner cases) since
we use the x86 cpu native ALU flags (which are more or less the same as
ARM's). Passes all test ROMs for ALUs and no changes in game compat.
Cleans up a ton of whitespace in cpu.c (like 100KB!) and improves
readability of some massive decode statements.
Added an optimization for PC-relative loads (pool load) in ROM (since
it's read only and cannot possibily change) that directly emits an
immediate load. This is way faster, specially in MIPS/x86, ARM can be
even faster if we rewrite the immediate load macros to also use a pool.
This saves a few cycles in MIPS and simplifies a bit the core.
Removed the write map, only affects interpreter performance very
minimally. Rewired ARM and x86 handlers to support direct access to
I/EWRAM (and VRAM on ARM) to compensate. Overall performance is slightly
better but code is cleaner and allows for further improvements in the
dynarecs.