Added stub implementations for dl*() functions

photon/libc/include/dlfcn.h

@@ -0,0 +1,14 @@
+#ifndef DLFCN_H_
+#define DLFCN_H_
+
+#define RTLD_LAZY   0
+#define RTLD_NOW    1
+#define RTLD_GLOBAL 2
+#define RTLD_LOCAL  3
+
+extern void *dlopen(const char *path, int mode);
+extern void *dlsym(void *handle, const char *name);
+extern int dlclose(void *handle);
+extern char *dlerror(void);
+
+#endif

photon/libc/sys/horizon/dlfcn.c

@@ -0,0 +1,30 @@
+#include <magenta/types.h>
+#include <stddef.h>
+#include <dlfcn.h>
+
+
+__attribute__((weak)) void *dyld_load_object(mx_handle_t handle, int mode) { return NULL; }
+__attribute__((weak)) void *dyld_get_symbol(void *handle, const char *name) { return NULL; }
+__attribute__((weak)) int dyld_close_object(void *handle) { return 0; }
+__attribute__((weak)) char *dyld_get_error(void) { return NULL; }
+
+void *dlopen(const char *path, int mode)
+{
+    dyld_load_object(MX_NULL_HANDLE, 0);
+    return NULL;
+}
+
+void *dlsym(void *handle, const char *name)
+{
+    return NULL;
+}
+
+int dlclose(void *handle)
+{
+    return 0;
+}
+
+char *dlerror(void)
+{
+    return NULL;
+}