[riscv] impl lb, lh, lbu, lhu, lwu
[riscv] impl lb, lh, lbu, lhu, lwu

futurecore/pydgin,cornell-brg/pydgin,cornell-brg/pydgin,futurecore/pydgin,futurecore/pydgin,cornell-brg/pydgin,futurecore/pydgin,cornell-brg/pydgin