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

fusl/src/math/scalbf.c

+/* origin: FreeBSD /usr/src/lib/msun/src/e_scalbf.c */
+/*
+ * Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com.
+ */
+/*
+ * ====================================================
+ * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
+ *
+ * Developed at SunPro, a Sun Microsystems, Inc. business.
+ * Permission to use, copy, modify, and distribute this
+ * software is freely granted, provided that this notice
+ * is preserved.
+ * ====================================================
+ */
+
+#define _GNU_SOURCE
+#include <math.h>
+
+float scalbf(float x, float fn)
+{
+        if (isnan(x) || isnan(fn)) return x*fn;
+        if (!isfinite(fn)) {
+                if (fn > 0.0f)
+                        return x*fn;
+                else
+                        return x/(-fn);
+        }
+        if (rintf(fn) != fn) return (fn-fn)/(fn-fn);
+        if ( fn > 65000.0f) return scalbnf(x, 65000);
+        if (-fn > 65000.0f) return scalbnf(x,-65000);
+        return scalbnf(x,(int)fn);
+}