subroutine_arg4 generated but never declared

[joshlory]

I've seen a few scratches now where subroutine_argN is generated in the decompilation but never declared:

• https://decomp.me/scratch/mKxBh
• https://decomp.me/scratch/YGyQp

Sometimes I can just replace it with s4 or the equivalent sN but in that last example it seems to be missing an entire code block:

 4c:    andi    v0,v0,0x7f00
 50:    sh      v0,0x10(sp)

...which is then used later as:

 184:    lhu     a3,0x10(sp)
 188:    nop
 18c:    beqz    a3,1a4 ~>

[joshlory]

Might be fixed by #235?