Register access (dynamic and static) wired up.

src/alloy/backend/ivm/ivm_intcode.h

@@ -14,6 +14,7 @@
 
 #include <alloy/hir/instr.h>
 #include <alloy/hir/opcodes.h>
+#include <alloy/runtime/register_access.h>
 
 namespace alloy { namespace runtime { class ThreadState; } }
 
@@ -43,6 +44,7 @@ typedef struct {
   uint8_t*      context;
   uint8_t*      membase;
   int8_t        did_carry;
+  runtime::RegisterAccessCallbacks* access_callbacks;
   runtime::ThreadState* thread_state;
   uint64_t      return_address;
 } IntCodeState;
@@ -85,6 +87,8 @@ typedef struct LabelRef_s {
 
 
 typedef struct {
+  runtime::RegisterAccessCallbacks* access_callbacks;
+
   uint32_t  register_count;
   size_t    intcode_count;
   Arena*    intcode_arena;