Fix remaining issues, move setjmp into relibc crate, move start logic into relibc

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

@@ -0,0 +1,20 @@
+.global _longjmp
+.global longjmp
+.type _longjmp,@function
+.type longjmp,@function
+_longjmp:
+longjmp:
+	mov  4(%esp),%edx
+	mov  8(%esp),%eax
+	test    %eax,%eax
+	jnz 1f
+	inc     %eax
+1:
+	mov   (%edx),%ebx
+	mov  4(%edx),%esi
+	mov  8(%edx),%edi
+	mov 12(%edx),%ebp
+	mov 16(%edx),%ecx
+	mov     %ecx,%esp
+	mov 20(%edx),%ecx
+	jmp *%ecx

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

@@ -0,0 +1,23 @@
+.global ___setjmp
+.hidden ___setjmp
+.global __setjmp
+.global _setjmp
+.global setjmp
+.type __setjmp,@function
+.type _setjmp,@function
+.type setjmp,@function
+___setjmp:
+__setjmp:
+_setjmp:
+setjmp:
+	mov 4(%esp), %eax
+	mov    %ebx, (%eax)
+	mov    %esi, 4(%eax)
+	mov    %edi, 8(%eax)
+	mov    %ebp, 12(%eax)
+	lea 4(%esp), %ecx
+	mov    %ecx, 16(%eax)
+	mov  (%esp), %ecx
+	mov    %ecx, 20(%eax)
+	xor    %eax, %eax
+	ret