Move setjmp and sigsetjmp together

This fixes compilation of relibc on arm64. On arm64 the reference from
sigsetjmp to setjmp has a limited range.

src/header/setjmp/impl/aarch64/sigsetjmp.s

@@ -0,0 +1,21 @@
+.global sigsetjmp
+.global __sigsetjmp
+.type sigsetjmp,%function
+.type __sigsetjmp,%function
+sigsetjmp:
+__sigsetjmp:
+	cbz x1,setjmp
+
+	str x30,[x0,#176]
+	str x19,[x0,#176+8+8]
+	mov x19,x0
+
+	bl setjmp
+
+	mov w1,w0
+	mov x0,x19
+	ldr x30,[x0,#176]
+	ldr x19,[x0,#176+8+8]
+
+.hidden __sigsetjmp_tail
+	b __sigsetjmp_tail

src/header/setjmp/impl/i386/sigsetjmp.s

@@ -0,0 +1,26 @@
+.global sigsetjmp
+.global __sigsetjmp
+.type sigsetjmp,@function
+.type __sigsetjmp,@function
+sigsetjmp:
+__sigsetjmp:
+	mov ecx, dword ptr [esp + 8]
+	jecxz 1f
+
+	mov eax, dword ptr [esp + 4]
+	pop [eax + 24]
+	mov dword ptr [eax * 8 + 28], ebx
+	mov ebx, eax
+
+.hidden ___setjmp
+	call ___setjmp
+
+	push [ebx + 24]
+	mov dword ptr [esp + 4], ebx
+	mov dword ptr [esp + 4], eax
+	mov ebx, dword ptr [ebx * 8 + 28]
+
+.hidden __sigsetjmp_tail
+	jmp __sigsetjmp_tail
+
+1:	jmp ___setjmp

src/header/setjmp/impl/riscv64/sigsetjmp.S

@@ -0,0 +1,23 @@
+.global sigsetjmp
+.global __sigsetjmp
+.type sigsetjmp, %function
+.type __sigsetjmp, %function
+sigsetjmp:
+__sigsetjmp:
+	bnez a1, 1f
+	tail setjmp
+1:
+
+	sd ra, 208(a0)
+	sd s0, 224(a0)
+	mv s0, a0
+
+	call setjmp
+
+	mv a1, a0
+	mv a0, s0
+	ld s0, 224(a0)
+	ld ra, 208(a0)
+
+.hidden __sigsetjmp_tail
+	tail __sigsetjmp_tail

src/header/setjmp/impl/x86_64/sigsetjmp.s

@@ -0,0 +1,24 @@
+.global sigsetjmp
+.global __sigsetjmp
+.type sigsetjmp,@function
+.type __sigsetjmp,@function
+sigsetjmp:
+__sigsetjmp:
+	test esi, esi
+	jz 1f
+
+	pop [rdi + 64]
+	mov qword ptr [rdi * 8 + 72], rbx
+	mov rbx, rdi
+
+	call setjmp
+
+	push [rbx + 64]
+	mov rdi, rbx
+	mov esi, eax
+	mov rbx, qword ptr [rbx * 8 + 72]
+
+.hidden __sigsetjmp_tail
+	jmp __sigsetjmp_tail
+
+1:	jmp setjmp