if syntax

include/picrin.h

@@ -23,7 +23,7 @@ typedef struct {
   pic_callinfo *ci;
   pic_callinfo *cibase, *ciend;
 
-  pic_value sDEFINE, sLAMBDA, sCONS;
+  pic_value sDEFINE, sLAMBDA, sIF, sCONS;
   pic_value sADD, sSUB, sMUL, sDIV;
   struct pic_env *global_env;
 

include/picrin/irep.h

@@ -9,6 +9,8 @@ enum pic_instruction {
   OP_GREF,
   OP_GSET,
   OP_LREF,
+  OP_JMP,
+  OP_JMPIF,
   OP_CALL,
   OP_RET,
   OP_LAMBDA,