feat(asm): encode indirect JMP and CALL on all four architectures

Assisted-by: GLM 5.3 Flash

asm/riscv_frame.go

@@ -93,12 +93,19 @@ func riscvIsLeaf(t *ast.Text) bool {
 				return false
 			}
 		case "JALR":
-			// JALR rs1, rd, a call when rd is X1; JALR offset(rs1) always
-			// links to X1.
+			// JALR rd, offset(rs1) links when the destination register (the
+			// first operand) is X1; JALR rs1, rd links when the second
+			// register is X1; JALR offset(rs1) always links to X1.
 			if len(in.Operands) == 1 {
 				return false
 			}
-			if len(in.Operands) >= 2 && regFromOperand(in.Operands[1]) == 1 {
+			if isMemOperand(in.Operands[1]) {
+				if regFromOperand(in.Operands[0]) == 1 {
+					return false
+				}
+				continue
+			}
+			if regFromOperand(in.Operands[1]) == 1 {
 				return false
 			}
 		}