[MIPS] reduce floating point registers

[Shinpei Kato]

Hi, there.
I want to reduce the number of floating point registers to 8 from 32.
I tried modifying mips.c and mips.h as attached files (mips.c.diff & 
mips.h.diff).
But I got errors as discribed in error.log. It seems a problem is 
something about HI_REG.
However I can't see how I can correct these errors.
Is there any other files I should modify to reduce them?

Could you tell me solutions or any hints?

Regards,
Shinpei Kato