[BasicAA] Add test showing incorrect noalias result with wrapping.

@mul_may_overflow_var_nonzero_minabsvarindex_one_index shows BasicAA
incorrectly determining noalias for (%gep.917, i8* %gep.idx).
If %v == 10581764700698480926, %idx == 917 and the GEPs alias.
https://alive2.llvm.org/ce/z/yzDgnn