Fix factorial trace (Funcsim)

[pavelkryukov]

Currently factorial fails on instruction 62:

./perf_sim -b ../tests/samples/factorial.out -n 100 -d -f

jr $ra
perf_sim: ../func_sim/func_memory/func_memory.cpp:79: uint64 FuncMemory::read(uint64, short unsigned int) const: Assertion `check( addr)' failed.

The problem is that jal istruction does not perform writeback to $ra register.

[gkorepanov]

The solution seems to be straightforward: I just have to add dst setting into initR and initJ:

dst = REG_NUM_RA

The problem is that it shouldn't be done for j and jr instructions, only for jal and jalr. So I have to discriminate them somehow. But now initJ, initR, initI are discriminating instructions only by operation type without looking at funct or opcode. So I had better add new operation type like

OUT_J_JUMPL // jal
OUT_J_JUMP  // ja
OUT_R_JUMPL // jalr
OUT_R_JUMP  // jr,

hadn't I?

[pavelkryukov]

Right.

I'd use more clear name, like 'JUMP_LINK'

[pavelkryukov]

Instruction JALR was not implemented correctly: it can store address not to RA only, but to any register specified in rd bits. Fixed now.