Improve the state of handwritten assembly files (#865)

* Format all handwritten asm and document some

* Use c preprocessor for constants

* Fix

* Fix PI_STATUS_ERROR, some label improvements

* Avoid hi/lo for constants

* Some more comments

* Properly mark functions as functions and their sizes

* Fix merge

* Improvements

* Review suggestions, rework procedure start/end macros to be more like libreultra

* Move IPL3 symbol definitions into ipl3.s

* Fix undefined_syms, add include and language guards to asm.h and fix the comment in gbi.h

* Consistent hex capitalization, add some MIPS builtin defines to CC_CHECK to behave properly

* Add -no-pad-sections assembler option and clean up alignment in gu files and bzero

* Further suggestions and improvements

* Matrix conversion function clarifications

* Fix passing AVOID_UB to gcc

* Suggestions

* Suggestions, global interrupt mask improvements

* Further suggestions, interrupt mask comments

* Comments fixes, rdb.h

* Switch from # comments to // comments, remove unnecesary .set gp=64 directives

* Further review suggestions

* Missed one

asm/osGetCount.s

@@ -1,15 +1,15 @@
-.include "macro.inc"
+#include "ultra64/asm.h"
+#include "ultra64/r4300.h"
 
-# assembler directives
-.set noat      # allow manual use of $at
-.set noreorder # don't insert nops after branches
-.set gp=64     # allow use of 64-bit general purpose registers
+.set noat
+.set noreorder
 
 .section .text
 
 .balign 16
-  
-glabel osGetCount
-/* 007AA0 80006EA0 40024800 */  mfc0  $v0, $9
-/* 007AA4 80006EA4 03E00008 */  jr    $ra
-/* 007AA8 80006EA8 00000000 */   nop   
+
+LEAF(osGetCount)
+    mfc0    $v0, C0_COUNT
+    jr      $ra
+     nop
+END(osGetCount)