[clang] Warn about memset/memcpy to NonTriviallyCopyable types (#111434)

This implements a warning that's similar to what GCC does in that
context: both memcpy and memset require their first and second operand
to be trivially copyable, let's warn if that's not the case.
GitOrigin-RevId: 71315698c91d0cda054b903da0594ca6f072c350
3 files changed