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

fusl/src/env/__reset_tls.c

Index: fusl/src/env/__reset_tls.c
diff --git a/fusl/src/env/__reset_tls.c b/fusl/src/env/__reset_tls.c
new file mode 100644
index 0000000000000000000000000000000000000000..677e57f58b45c6db27c9d1f0ceda3f1b72b08c95
--- /dev/null
+++ b/fusl/src/env/__reset_tls.c
@@ -0,0 +1,16 @@
+#include <string.h>
+#include "pthread_impl.h"
+#include "libc.h"
+
+void __reset_tls()
+{
+	pthread_t self = __pthread_self();
+	struct tls_module *p;
+	size_t i, n = (size_t)self->dtv[0];
+	if (n) for (p=libc.tls_head, i=1; i<=n; i++, p=p->next) {
+		if (!self->dtv[i]) continue;
+		memcpy(self->dtv[i], p->image, p->len);
+		memset((char *)self->dtv[i]+p->len, 0,
+			p->size - p->len);
+	}
+}