LibC: Implement {sig,_,}{longjmp,setjmp}

userspace/libraries/LibC/arch/i686/setjmp.S

@@ -0,0 +1,28 @@
+// int setjmp(jmp_buf env)
+.global setjmp
+setjmp:
+	movl 4(%esp), %edx
+
+	leal 4(%esp), %eax
+	movl %eax, 0(%edx)
+
+	movl (%esp), %eax
+	movl %eax, 4(%edx)
+
+	xorl %eax, %eax
+
+	ret
+
+// void longjmp(jmp_buf env, int val)
+.global longjmp
+longjmp:
+	movl 4(%esp), %edx
+
+	movl 8(%esp), %ecx
+	movl $1, %eax
+	testl %ecx, %ecx
+	cmovnzl %ecx, %eax
+
+	movl 0(%edx), %esp
+	movl 4(%edx), %ecx
+	jmp *%ecx