[fuzzer] Improve memory constraints

[tonkosi]

Improved checks:

• Don't take addresses of reference / virtually inherited fields in expressions such as &(invalid_struct_ptr)->virt_or_ref_field. In general, this kind of expression is OK because compiler can determine offset of the field statically and add it to the pointer. But reference fields and virtually inherited fields require a read from memory to determine the offset.
• Don't cast between different pointer types if read from memory is expected, e.g. *(int*)float_ptr, or ((StructB*)struct_a_ptr)->field.

[github-actions]

Benchmark comparison for fb84fb26 (base) vs df8b4894 (PR)

Benchmark                             Time             CPU      Time Old      Time New       CPU Old       CPU New
------------------------------------------------------------------------------------------------------------------
BM/AddTwoNumbers                   +0.0133         +0.0127        136617        138431        136607        138347
BM/ArrayDereference                -0.0009         -0.0009        142333        142205        142323        142195
BM/ArraySubscript                  +0.0054         +0.0058        186453        187459        186365        187444
BM/TypeCasting                     +0.0014         +0.0014        486141        486814        486096        486756
BM/ParseInteger                    +0.0050         +0.0050        200688        201683        200667        201670