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

fusl/src/complex/cabsl.c

Index: fusl/src/complex/cabsl.c
diff --git a/fusl/src/complex/cabsl.c b/fusl/src/complex/cabsl.c
new file mode 100644
index 0000000000000000000000000000000000000000..40a067c1c59f182d7d96957a3286e4dace5e5449
--- /dev/null
+++ b/fusl/src/complex/cabsl.c
@@ -0,0 +1,13 @@
+#include "libm.h"
+
+#if LDBL_MANT_DIG == 53 && LDBL_MAX_EXP == 1024
+long double cabsl(long double complex z)
+{
+	return cabs(z);
+}
+#else
+long double cabsl(long double complex z)
+{
+	return hypotl(creall(z), cimagl(z));
+}
+#endif