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

fusl/arch/mips/ksigaction.h

Index: fusl/arch/mips/ksigaction.h
diff --git a/fusl/arch/mips/ksigaction.h b/fusl/arch/mips/ksigaction.h
new file mode 100644
index 0000000000000000000000000000000000000000..3127f7c0218333196945bca4139c3ef0c3df4483
--- /dev/null
+++ b/fusl/arch/mips/ksigaction.h
@@ -0,0 +1,11 @@
+struct k_sigaction {
+	unsigned flags;
+	void (*handler)(int);
+	unsigned long mask[4];
+	/* The following field is past the end of the structure the
+	 * kernel will read or write, and exists only to avoid having
+	 * mips-specific preprocessor conditionals in sigaction.c. */
+	void (*restorer)();
+};
+
+void __restore(), __restore_rt();