Hello,

This patch eliminates the macro MIPS_REGISTER_TYPE.  In doing this some 
subtle bugs have been fixed:

- n32 integer registers are 64-bits
N32 is a hybrid 32/64-bit ABI.  While void* is 32-bits, the full 64-bits 
of each register are stored on the stack and the full 64-bits of each 
register is visible.  Previously, on IRIX, an n32 evironment had 32-bit 
registers.

- The integer registers are now always signed (int32_t or int64_t).
MIPS has signed addresses so signed registers are more consistent with 
this.  Previously, the signness/type of each register was pot luck.

committed,
Andrew