16/32 stack operations fix on x86_64 (aka win2000 startup bug)

git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@1540 c046a42c-6fe2-441c-8c8c-71466251a162

target-i386/op.c

@@ -865,7 +865,7 @@ void OPPROTO op_decq_ECX(void)
 
 void op_addl_A0_SS(void)
 {
-    A0 += (long)env->segs[R_SS].base;
+    A0 = (uint32_t)(A0 + env->segs[R_SS].base);
 }
 
 void op_subl_A0_2(void)