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

fusl/src/setjmp/arm/setjmp.s

Index: fusl/src/setjmp/arm/setjmp.s
diff --git a/fusl/src/setjmp/arm/setjmp.s b/fusl/src/setjmp/arm/setjmp.s
new file mode 100644
index 0000000000000000000000000000000000000000..87791634b862313f69168c6742fe2e3fa35c5c15
--- /dev/null
+++ b/fusl/src/setjmp/arm/setjmp.s
@@ -0,0 +1,42 @@
+.syntax unified
+.global __setjmp
+.global _setjmp
+.global setjmp
+.type __setjmp,%function
+.type _setjmp,%function
+.type setjmp,%function
+__setjmp:
+_setjmp:
+setjmp:
+	mov ip,r0
+	stmia ip!,{v1,v2,v3,v4,v5,v6,sl,fp,sp,lr}
+	mov r0,#0
+
+	adr r1,1f
+	ldr r2,1f
+	ldr r1,[r1,r2]
+
+	tst r1,#0x260
+	beq 3f
+	tst r1,#0x20
+	beq 2f
+	stc p2, cr4, [ip], #48
+2:	tst r1,#0x40
+	beq 2f
+	.fpu vfp
+	vstmia ip!, {d8-d15}
+	.fpu softvfp
+	.eabi_attribute 10, 0
+	.eabi_attribute 27, 0
+2:	tst r1,#0x200
+	beq 3f
+	stcl p1, cr10, [ip], #8
+	stcl p1, cr11, [ip], #8
+	stcl p1, cr12, [ip], #8
+	stcl p1, cr13, [ip], #8
+	stcl p1, cr14, [ip], #8
+	stcl p1, cr15, [ip], #8
+3:	bx lr
+
+.hidden __hwcap
+1:	.word __hwcap-1b