Hi,

On MIPS R4000 CPU, LLAddr register is read-write, whereas on MIPS64 
specification, it is read-only.
Attached patch adds a new instruction flag (INSN_R4000), which is 
checked to know if register is writable.

Also, it changes the return format of the LLAddr register, which is 
defined as implementation-dependant in MIPS64, so it shouldn't hurt.

Hervé