Issue 13841 - infinite loop in compiler on simd arithmetic

https://issues.dlang.org/show_bug.cgi?id=13841

All vector types should have no common types between different vectors, even though their sizes are same.


If this condition check does not exist, `Tvector` vs `Tvector` will hit the condition `else if (t1->isintegral() && t2->isintegral())` and fall into the infinite recursion.