Places the value 1 in register `xd` if register `xs1` is less than the sign-extended immediate when both are treated as unsigned numbers (_i.e._, the immediate is first sign-extended to XLEN bits then treated as an unsigned number), else 0 is written to `xd`. NOTE: `sltiu xd, xs1, 1` sets `xd` to 1 if `xs1` equals zero, otherwise sets `xd` to 0 (assembler pseudoinstruction `SEQZ xd, rs`).
sltiu xd, xs1, immType: I