[clang-tidy] Make `P +- BS / sizeof(*P)` opt-outable in `bugprone-sizeof-expression` (#111178)

In some cases and for projects that deal with a lot of low-level buffers, a
pattern often emerges that

[clang-tidy] Make `P +- BS / sizeof(*P)` opt-outable in `bugprone-sizeof-expression` (#111178)

In some cases and for projects that deal with a lot of low-level buffers, a
pattern often emerges that an array and its full size, not in the number of
"elements" but in "bytes", are known with no syntax-level connection between
the two values.
To access the array elements, the pointer arithmetic involved will have
to divide 'SizeInBytes' (a numeric value) with `sizeof(*Buffer)`.
Since the previous patch introduced this new warning, potential
false-positives were triggered from `bugprone-sizeof-expression`, as `sizeof`
appeared in pointer arithmetic where integers are scaled.

This patch adds a new check option, `WarnOnOffsetDividedBySizeOf`, which allows
users to opt out of warning about the division case.
In arbitrary projects, it might still be worthwhile to get these warnings until
an opt-out from the detection of scaling issues, especially if a project
might not be using low-level buffers intensively.

show more ...