Split out context object into jitstate_t and ctx_t

ujit_codegen.h

@@ -7,8 +7,25 @@
 codeblock_t* cb;
 codeblock_t* ocb;
 
+// Code generation state
+typedef struct JITState
+{
+    // Instruction sequence this is associated with
+    const rb_iseq_t *iseq;
+
+    // Index in the iseq of the opcode we are replacing
+    uint32_t start_idx;
+
+    // Index of the current instruction being compiled
+    uint32_t insn_idx;
+
+    // Current PC
+    VALUE *pc;
+
+} jitstate_t;
+
 // Code generation function signature
-typedef bool (*codegen_fn)(codeblock_t* cb, codeblock_t* ocb, ctx_t* ctx);
+typedef bool (*codegen_fn)(jitstate_t* jit, ctx_t* ctx);
 
 uint8_t* ujit_compile_entry(const rb_iseq_t *iseq, uint32_t insn_idx);