move to meson for build system

src/gc.h

@@ -0,0 +1,31 @@
+#ifndef GC_H
+#define GC_H
+
+#include "common.h"
+#include "object.h"
+
+#define GC_DEBUG 1
+#define HEAP_BYTES (4 * 1024 * 1024)
+
+typedef struct Gs {
+  U8 *start, *end;
+  U8 *free;
+} Gs;
+
+typedef struct Gc {
+  Gs from, to;
+  struct {
+    O **items;
+    Z count, capacity;
+  } roots;
+} Gc;
+
+V gc_addroot(Gc *, O *);
+I gc_mark(Gc *);
+V gc_reset(Gc *, I);
+V gc_collect(Gc *);
+Hd *gc_alloc(Gc *, Z);
+V gc_init(Gc *);
+V gc_deinit(Gc *);
+
+#endif