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

fusl/src/prng/__rand48_step.c

Index: fusl/src/prng/__rand48_step.c
diff --git a/fusl/src/prng/__rand48_step.c b/fusl/src/prng/__rand48_step.c
new file mode 100644
index 0000000000000000000000000000000000000000..961d30fc9161e48dde6fc64a9c8aa10f19f5eee5
--- /dev/null
+++ b/fusl/src/prng/__rand48_step.c
@@ -0,0 +1,13 @@
+#include <stdint.h>
+
+uint64_t __rand48_step(unsigned short *xi, unsigned short *lc)
+{
+	uint64_t a, x;
+	x = xi[0] | xi[1]+0U<<16 | xi[2]+0ULL<<32;
+	a = lc[0] | lc[1]+0U<<16 | lc[2]+0ULL<<32;
+	x = a*x + lc[3];
+	xi[0] = x;
+	xi[1] = x>>16;
+	xi[2] = x>>32;
+	return x & 0xffffffffffffull;
+}