start implementing the libretro interface. (not working yet)

libco.h

@@ -0,0 +1,37 @@
+/*
+  libco
+  version: 0.16 (2010-12-24)
+  license: public domain
+*/
+
+#ifndef LIBCO_H
+#define LIBCO_H
+
+#ifdef LIBCO_C
+  #ifdef LIBCO_MP
+    #define thread_local __thread
+  #else
+    #define thread_local
+  #endif
+#endif
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+typedef void* cothread_t;
+
+cothread_t co_active(void);
+
+cothread_t co_create(unsigned int, void (*)(void));
+
+void co_delete(cothread_t);
+
+void co_switch(cothread_t);
+
+#ifdef __cplusplus
+}
+#endif
+
+/* ifndef LIBCO_H */
+#endif