Try to allocate executable memory close to PPSSPP memory if not below 4GB
executable memory allocation changes
fix 32-bit builds
Note the location of a memset variant.
Premultiply for doubled alpha blending if possible.

This makes the effect more accurate where the values were being clamped
before.  Some obscure methods of blending may be slower.
Avoid recalculating replaceBlend so many times.
Avoid premultiplying easy fixed colors.
Dirty the fixed color when premultiplying.
Avoid using fbo copies for the common 2a + 1-2a.

We won't even get it right that often since the copy doesn't deal with
overlap properly.
Improve a possible obscure blend mode.

Seems like this would be likely to get overlap problems.
Optimize fixed color blending that isn't blending.

Gods Eater Burst uses this, for example.
More correctly blend when hitting the frame cap.

If we hit too many blits per frame, fall back correctly in the shader.
Add a hack for Silent Hill games.

Either way has different problems, but it sounds like this will work
better for Silent Hill.  Probably still rendering wrong, unfortunately.
x86jit: Support fpu rounding modes for mul, etc.

Fixes Gods Eater Burst loading PSP savedata, but can no longer load old
savedata.
x86jit: Implement cvt.w.s.

Not really used that often, anyway, but easy enough and good for testing
that we set the rounding mode correctly.
armjit: Respect the rounding mode for mul/etc.
Add a frontend option for GEB saves.

May also affect performance, so can be disabled for that.
Merge pull request #6679 from unknownbrackets/gpu-blend

Handle doubled alpha blending using premultiplication
x86jit: Maintain the rounding mode always.

This should be less often than doing it per block that uses fpu, unless
the game doesn't use fpu much at all.
(Partially) slip thin3d underneath DrawBuffer.