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

fusl/include/stdarg.h

Index: fusl/include/stdarg.h
diff --git a/fusl/include/stdarg.h b/fusl/include/stdarg.h
new file mode 100644
index 0000000000000000000000000000000000000000..60d4e2af172fad8acfd1c91f8fe6f1ff74622871
--- /dev/null
+++ b/fusl/include/stdarg.h
@@ -0,0 +1,25 @@
+#ifndef _STDARG_H
+#define _STDARG_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#define __NEED_va_list
+
+#include <bits/alltypes.h>
+
+#if __GNUC__ >= 3
+#define va_start(v,l)   __builtin_va_start(v,l)
+#define va_end(v)       __builtin_va_end(v)
+#define va_arg(v,l)     __builtin_va_arg(v,l)
+#define va_copy(d,s)    __builtin_va_copy(d,s)
+#else
+#include <bits/stdarg.h>
+#endif
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif