Zba Extension

8 instructions and 1 pseudo-instructions in the Zba extension.

• add.uw - Add unsigned word
• sh1add - Shift left by 1 and add
• sh1add.uw - Shift unsigned word left by 1 and add
• sh2add - Shift left by 2 and add
• sh2add.uw - Shift unsigned word left by 2 and add
• sh3add - Shift left by 3 and add
• sh3add.uw - Shift unsigned word left by 3 and add
• slli.uw - Shift left unsigned word (Immediate)
• zext.w - Pseudo-Instruction (→ add.uw)