Add a "fork" of musl as //fusl.

fusl/src/misc/basename.c

Index: fusl/src/misc/basename.c
diff --git a/fusl/src/misc/basename.c b/fusl/src/misc/basename.c
new file mode 100644
index 0000000000000000000000000000000000000000..cc4f778c518b8f01b86269c9904952906009fce5
--- /dev/null
+++ b/fusl/src/misc/basename.c
@@ -0,0 +1,15 @@
+#include <string.h>
+#include <libgen.h>
+#include "libc.h"
+
+char *basename(char *s)
+{
+	size_t i;
+	if (!s || !*s) return ".";
+	i = strlen(s)-1;
+	for (; i&&s[i]=='/'; i--) s[i] = 0;
+	for (; i&&s[i-1]!='/'; i--);
+	return s+i;
+}
+
+weak_alias(basename, __xpg_basename);