Add a "fork" of musl as //fusl.
This is musl verbatim at d5f8394f6ea9549607567bd92de12a2446c15614.
See http://www.musl-libc.org/.
R=kulakowski@chromium.org
Review URL: https://codereview.chromium.org/1573973002 .
diff --git a/fusl/include/stdarg.h b/fusl/include/stdarg.h
new file mode 100644
index 0000000..60d4e2a
--- /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
