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

fusl/src/math/nearbyint.c

Index: fusl/src/math/nearbyint.c
diff --git a/fusl/src/math/nearbyint.c b/fusl/src/math/nearbyint.c
new file mode 100644
index 0000000000000000000000000000000000000000..f4e8aac4f0118d7d48d1d6a8e4af0fec048ee62a
--- /dev/null
+++ b/fusl/src/math/nearbyint.c
@@ -0,0 +1,20 @@
+#include <fenv.h>
+#include <math.h>
+
+/* nearbyint is the same as rint, but it must not raise the inexact exception */
+
+double nearbyint(double x)
+{
+#ifdef FE_INEXACT
+	#pragma STDC FENV_ACCESS ON
+	int e;
+
+	e = fetestexcept(FE_INEXACT);
+#endif
+	x = rint(x);
+#ifdef FE_INEXACT
+	if (!e)
+		feclearexcept(FE_INEXACT);
+#endif
+	return x;
+}