external instr_opcode : llvalue -> Opcode.t = "llvm_instr_get_opcode"
external icmp_predicate : llvalue -> Icmp.t option = "llvm_instr_icmp_predicate"
+external instr_clone : llvalue -> llvalue = "llvm_instr_clone"
let rec iter_instrs_range f i e =
if i = e then () else