SubS Shadows, Cutscenes, Exchange, and Planes (#773)

* Bring code over

* Rename

* clean up variables.h

* Bring over some more code as well as cleanup

* remove newline in functions.h

* format

* Add plane functions

* Remove from actorfixer

* Add some more docs to plane functions

* Use temp for better format

* change func_8013E8F8 to return an s32

* rename origin back to pos

* format

* Add docs to SubS_ComputePlane

* format

* gfxContextPtr -> globalCtx

* bss

* Better docs of SubS_ComputePlane

* Normal -> unitVec

* Review pt. 1

* Update plane comment

* SubS_ActorAndPlayerAreFacing -> SubS_ActorAndPlayerFaceEachOther

* Add subs texture defines

* Update include/z64math.h

Co-authored-by: EllipticEllipsis <elliptic.ellipsis@gmail.com>

Co-authored-by: EllipticEllipsis <elliptic.ellipsis@gmail.com>

src/boot_O2_g3/yaz0.c

@@ -1,4 +1,3 @@
-#include "prevent_bss_reordering.h"
 #include "global.h"
 
 u8 sYaz0DataBuffer[0x400];