Reorganize packages

src/runtime/runtime.h

@@ -0,0 +1,11 @@
+
+#pragma once
+
+#include <stdint.h>
+
+typedef struct {
+	uint32_t len;  // TODO: size_t (or, let max string size depend on target/flag)
+	uint8_t  *buf; // points to string buffer itself
+} string_t;
+
+typedef int32_t intgo_t; // may be 64-bit