fix msvc

vendor/mruby-compiler2/include/mrc_proc.h

@@ -0,0 +1,30 @@
+#ifndef MRC_PROC_H
+#define MRC_PROC_H
+
+MRC_BEGIN_DECL
+
+#define MRC_OBJECT_HEADER \
+  struct RClass *c;       \
+  struct RBasic *gcnext;  \
+  enum mrb_vtype tt:8;    \
+  unsigned int gc_color:3; \
+  unsigned int frozen:1;  \
+  uint32_t flags:20
+
+struct RProc {
+  MRC_OBJECT_HEADER;
+  union {
+    const mrc_irep *irep;
+    mrb_func_t func;
+    mrb_sym mid;
+  } body;
+  const struct RProc *upper;
+  union {
+    struct RClass *target_class;
+    struct REnv *env;
+  } e;
+};
+
+MRC_END_DECL
+
+#endif // MRC_PROC_H