[analyzer] MallocChecker: Recognize std::atomics in smart pointer suppression. (#90918)

Fixes #90498.

Same as 5337efc6 for atomic builtins, but for `std::atomic` this
time. This is useful because even though the actual builtin atomic is
still there, it may be buried beyond the inlining depth limit.

Also add one popular custom smart pointer class name to the name-based
heuristics, which isn't necessary to fix the bug but arguably a good
idea regardless.