Add more libc header stuff

base/usr/include/dlfcn.h

@@ -1,9 +1,13 @@
 #pragma once
 
-#define RTLD_LAZY 0
-#define RTLD_NOW  1
+/* Currently unused... */
+#define RTLD_LAZY   (1 << 0)
+#define RTLD_NOW    (1 << 1)
+#define RTLD_GLOBAL (1 << 2)
 
+#define RTLD_DEFAULT ((void*)0)
 
+/* Provided by ld.so, but also defined by libc.so for linking */
 extern void * dlopen(const char *, int);
 extern int dlclose(void *);
 extern void * dlsym(void *, const char *);

base/usr/include/sys/mman.h

@@ -0,0 +1,3 @@
+#pragma once
+
+/* Nothing here, we don't have an mmap implementation yet? */