[clang-format] distinguish multiplication after brace-init from pointer

After https://github.com/llvm/llvm-project/commit/b646f0955574c6ad4c156c9db522e46f597cfda9,
the added regression test started being formatted as-if the
multiplication `*` was a pointer. This adapts the heuristic to
distinguish between these two cases.

Reviewed By: jackhong12, curdeius, HazardyKnusperkeks, owenpan

Differential Revision: https://reviews.llvm.org/D129771