OP_BACKREFN_IC   1768 regcomp.c      	  r = add_opcode(reg, OP_BACKREFN_IC);
OP_BACKREFN_IC   6202 regcomp.c        { OP_BACKREFN_IC,         "backrefn-ic",          ARG_SPECIAL },
OP_BACKREFN_IC   6459 regcomp.c          case OP_BACKREFN_IC:
OP_BACKREFN_IC   2562 regexec.c          CASE(OP_BACKREFN_IC)  MOP_IN(OP_BACKREFN_IC);